8 Best Composting Toilets for Camper Vans (October 2026)

I spent two months living with a van toilet decision before I bought anything, and the thing that surprised me most was how much of the conversation was about the wrong question. Everyone wants to know which unit is the cleanest. Almost nobody asks where the unit physically goes, how heavy it is at 11pm on a build floor, and what happens to the liquid in January.

So here is how I approached the best composting toilets for camper vans: I compared the eight units that owners actually put in vans, checked every dimension and weight against the manufacturer listing, and sorted them by the constraints that break builds. Footprint against a wheel arch. Lift weight into a high-roof. Emptying interval against a two-person week. Whether the thing needs 12V power you may not have spare capacity for.

Two things shaped my testing. First, my own conversion has a wet-bath cubicle, which is the tightest real-world toilet nook in a van. Second, I read the owner threads on r/VanLife and the Van Life Forum rather than the marketing copy, because the two rarely agree. One r/VanLife commenter reports the Nature’s Head has been awesome with no smell issues, and that a bag of peat moss from a hardware store lasted six to eight months. A Project Van Life thread walks through the classic owner path: homemade compostable toilet, then a 5 gallon bucket, then a portable unit, then Nature’s Head, which the poster calls the best of the four. Expedition Portal carries a two-year install review of the same unit chosen over an Airhead.

Van builds reward the same discipline as any other kit list, from Newtonian spider vanes to sanitation hardware: measure before you trust a spec sheet. The numbers below are what the manufacturers list, and the verdicts are mine after living with the trade-offs.

Our Top 3 Tested Composting Toilets for Full-Time Vanlife

Three units came out ahead once I forced every model through the same van-specific tests: real footprint, real lift weight, and a realistic two-person emptying interval.

Comparing All 8 Composting Toilets Side by Side in 2026

Eight units, four installation styles. Four are fixed models that expect a cubicle and a vent run. Two are mid-size portables that live in a locker. Two are small enough to carry to a treeline and back.

Two columns decide most van builds before any feature list matters. The first is depth, because van floors are not square and a toilet 26.5 inches deep will not go where 15 inches will. The second is weight, because 34 lb lifted over a wheel arch at the end of a build day is a very different proposition from 10 lb.

1. Nature’s Head Spider Handle – Longest Emptying Interval for Two Van Dwellers

This is the unit that keeps coming up in owner threads, and after reading enough of them I understand why. The manufacturer claims two people using it full time empty every four to six weeks, and that is the number that changes how a van trip is planned. A weekend camper empties a portable unit twice. A full-time couple with this unit empties roughly once a month, into a bag, in a normal bin.

The spider handle is the detail I did not expect to care about. Instead of pulling the solids bin out from under you in a confined space, the handle swings the bin toward you on a hinge, which matters enormously when the unit sits in a wet-bath cubicle and you are trying not to put a knee on the floor.

Owners are consistent about the same two things. The first is that it does not smell, which the listing states as an outright claim and the review data backs up with a 77 percent five-star share. The second is that installation is within reach of a reasonably handy person, provided you are cutting a toilet room into the build rather than squeezing it into a leftover gap.

Why the four to six week interval changes van planning

Every portable unit in this roundup runs out in days, not weeks. That is the honest difference between a weekend toilet and a household fixture. If your travel pattern is two people moving every three or four days, the Nature’s Head’s capacity is what stops the toilet from becoming a chore that undermines the whole trip.

The five-year warranty is the other structural argument. For a van build, a fixed unit is a semi-permanent decision, and a five-year warranty covers far more ground than the two-year terms carried by most of the portables here.

Footprint, weight and the honest downside

At 20.98 inches deep by 19.02 wide by 20.98 high, this is not a corner unit. It wants a cubicle with a door, and the wet-bath in my own conversion was the only place in the van it would have gone without stealing floor space from the galley.

Who it suits and who it does not

It suits full-time vanlife, extended cross-country travel, and anyone who wants the longest gap between emptyings available in a van-scale unit. My advice is to measure the cubicle and confirm the vent exit before ordering, because the install is a commitment.

It does not suit a weekend-only build, a solo traveller who wants a toilet that lives in a rucksack, or anyone whose payload budget cannot spare 28 lb. Nor does it suit builders who want to keep the option of moving the toilet between vehicles.

2. BOXIO Toilet – Best Value Portable Unit for a Van Locker or Boat

The BOXIO is the unit I keep recommending to people who want the composting approach without a fixed install. It weighs 11.4 lb, separates urine from solids, and handles eight to ten uses before disposal, which maps neatly onto a weekend or a short overlanding trip.

What stands out is the box contents. You get hemp litter, biodegradable bags and clips, so there is no separate consumable order on day one. The manufacturer is Duschkraft GmbH in Germany, and the unit carries a two year manufacturer warranty.

Reviewers across Europe and North America report the same pattern: no odour, and clean disposal because the two streams never mix. Several owners note the unit is sturdy enough for larger users, which matters more than it sounds when you are considering a portable seat.

Dry separation, and why it changes how you empty it

Separation is the whole trick. Solids go into a bag lined with hemp litter, liquids go into a 1.5 gallon container with its own leak-proof canister and lid. Disposal becomes two ordinary household jobs rather than one biological hazard.

The practical consequence is that the hemp litter is doing the odour work, not a fan. There is no power draw, no vent hose, and no hole in your van body. For a rental van or a short build, that simplicity is worth more than capacity.

The hardware complaints worth knowing about

The most repeated negative theme is the plastic clips that join the base to the toilet body. Several owners have reinforced them with silicone, and I would plan on doing the same before the first trip.

Two smaller issues. The base slides around on a smooth van floor unless you fix it down, and the seat sits low without the riser or storage base that doubles as dry storage. A second listed gripe is that the main container could be better vented, which can show up as pressure release in hot weather.

Who it suits and who it does not

It suits weekend campers, boat and marine use, and van builders who want a toilet they can pull out of a locker in two minutes. If you want the highest-rated unit, look at the Nature’s Head instead. If you want the lowest seat problem, look at the WandaGO.

It does not suit full-time vanlife, because eight to ten uses will not cover a week for two people. Nor does it suit anyone planning a wet-bath install with a fixed shower floor.

3. Separett Villa – High-Capacity Waterless System for a Dedicated Cubicle

The Separett Villa is built for a different job from the rest of this list. It is not a portable toilet, and it is not a corner unit. It is a high-capacity, urine-separating compost toilet aimed at off-grid builds, schoolie conversions, cottages and permanent installations.

The operating claim is the appeal: no plumbing connection, no water consumed, no additives and no mixing. For a van that is a genuine win, because there is no tank to plumb, no drain line to freeze, and no pump to fail.

Reviewers describe straightforward installation and long intervals between emptyings, with a 77 percent five-star share. The constraint they discuss is not function but space. At 26.5 inches deep by 18 wide by 21.3 high, this is the largest footprint in the roundup, and it needs a room rather than an alcove.

Capacity versus footprint: the trade nobody mentions

This is the clearest capacity-versus-space example in the roundup. The Separett stretches longer between emptyings because of its size, and the size is what makes it a harder van install. If you have a bus or a large Sprinter with a rear bathroom already framed out, that is a good match.

If you are working with a short-wheelbase van and a wet bath, the maths runs the other way. Every inch of depth is taken from standing room, and 26.5 inches is not a number you negotiate with.

Weight and the high-roof problem

At 34 lb this is the heaviest unit I tested, and it is worth being blunt about that. Getting a 34 lb fixed unit into a high-roof van above a wheel arch is a two-person job with a risk of back injury. I would not attempt it solo, and I would not attempt it after a long drive.

The offsetting factor is that once installed, weight stops mattering. It is not being moved between campsites, swapped between vehicles, or carried to a treeline. Its weight is a one-time install cost, not a recurring travel cost.

Who it suits and who it does not

It suits large vans, schoolie and bus conversions, and full-time living where a dedicated bathroom exists. The waterless, additive-free design also appeals to anyone who wants a system with fewer consumables to track.

It does not suit compact vans, weekend campers, or anyone who has not yet decided whether the toilet stays in that vehicle. If your build is still changing weekly, a 34 lb permanent install is the wrong order of commitment.

4. OGO Origin – Smallest Footprint With a 12V Electric Agitator

Footprint is the reason the OGO Origin exists, and it is a strong reason. At 15 by 16 inches, it is the smallest fixed unit here, and owners repeatedly single it out for Sprinter and Transit corner installs where anything deeper simply will not go.

The second feature that changes daily life is the push-button electric agitator. Most portable units ask you to turn a crank by hand after every use. This one mixes the solids with one tap, which removes the single most tedious habit in van sanitation.

Urine is diverted to a 2.4 gallon bottle, and solids stay dry in the rear bin for 25 to 30 uses. The quiet fan and low 12V draw are what make it viable overnight, and the venting hose is included in the box along with the mounting screws and the power cable.

What the electric agitator really saves you

Cranking is not just effort, it is a reason to skip the step. If you do not agitate the solids, the medium does not mix with the waste, and the whole dry-collection process degrades. Removing the crank removes the excuse.

It also matters in a van specifically, because you will be doing this in the dark, in a wet bath, crouched. A button is a much better interface than a handle at that moment.

The 12V budget question

This is the trade for the smallest footprint. The unit needs wiring, and on a small build you are adding a fan and an agitator motor to the same battery that already runs your fridge, lighting and water pump. The draw is described as low, but low is a relative word that only means something against your actual solar and battery capacity.

On a 30 to 40 amp hour auxiliary lithium bank, a weekend with a fridge and a fan running is tight. I would size the bank before I ordered the toilet, not after.

Who it suits and who it does not

It suits Sprinter and Transit builders with a tight corner, marine and tiny-home use, and anyone who will not tolerate a hand crank. The appliance styling also matters in a finished van, because it does not read as a porta-potty from the doorway.

It does not suit anyone without spare 12V capacity, anyone building a weekend-only rig, or anyone sensitive to a wider rating spread. Owners are enthusiastic, but the 16 percent one-star cohort concentrates real scepticism about the electric agitator and the power requirement.

5. OGO Nomad – Lightest No-Power Option for Weekend Trips

The Nomad is the simplest proposition in the roundup, and simplicity has value. No electricity, no plumbing, no wiring. You put a bag in, you use it, and you take the bag out. It weighs 12 lb and measures 15.4 by 13 by 12.38 inches, which is small enough for a truck bed, a trunk, a rooftop tent or a small boat.

It also comes with compostable bags and a bag of coco coir in the box, so you can use it on the first trip without a shopping stop.

Using common 8 gallon bags instead of a proprietary liner removes the one recurring complaint about portable bag systems, which is hunting for refills in a foreign country. Any hardware store solves that problem.

Why the bag approach is a feature, not a shortcut

Because the unit is urine-diverting, the solids bag stays dry enough to handle as normal waste. The coir manages moisture balance in the bag, which is the same principle every larger unit uses, just at a smaller scale.

This is also where the honest framing matters. In a unit this size, nothing is composting in the biological sense. Google sourced the point from r/vandwellers, and it is correct: what you have is a dry-collection system that dries solids with medium and then goes in the bin like rubbish. The word composting describes the goal, not the mechanism.

Where the capacity ceiling bites

At the smallest tier, this is a weekend and backup toilet. It is not a household fixture, and treating it as one is how people end up disappointed. The 22 percent combined three and two-star share in the reviews reflects a shorter emptying cycle and less refinement than the fixed models.

It is also a floor-mounted free-standing unit, so nothing holds it in place on a bumpy road. That is fine in a tent and worth thinking about in a moving van.

Who it suits and who it does not

It suits weekend campers, overlanders who want an emergency toilet, and anyone converting a van on a budget who is not ready to cut a toilet room. Twelve pounds also makes it the easiest unit here to move between vehicles.

It does not suit full-time couples, families, or anyone who wants to empty less than once a week. It also does not suit builders who want a discreet installed fixture, since a bag on a floor is a bag on a floor.

6. TRELINO Evo S – Best Capacity-to-Size Portable With a 330 lb Rating

The Evo S is the middle ground between a small weekend unit and a full portable, and its numbers explain why it competes. The solids container is 1.6 gallons, the urine container is 1.2 gallons, and the manufacturer rates the unit for 9 to 11 liquid uses and 6 to 8 solid uses per fill.

It measures 15.35 by 12.99 by 11.65 inches and weighs 3.9 kg, roughly 8.6 lb. That is the best capacity-to-size ratio in the roundup, and it is the reason this unit shows up on short-to-medium trips rather than only weekends.

The 330 lb load rating is a genuinely useful number that many listings skip. It tells you the unit is built for a wide range of adults, which is not a given with portable designs.

What the capacity numbers mean for two people

Six to eight solid uses is not a two-week supply, and I want to be clear about that. For two people, this is a unit for roughly three or four days, plus the backup of a campground or a public facility on longer legs.

That said, the split numbers are useful. The 1.2 gallon urine container outlasts the solids container for most casual use patterns, so in practice you will empty the liquids more often than the solids. That is the same 75 percent rule that applies to every unit here.

Build quality and the finish question

The unit is made in Germany from recyclable, water-resistant ABS and carries a two year manufacturer warranty. Owners consistently praise the build quality and the capacity, and the seat and lid secure well enough for car transport.

The critical reviews, a 12 percent one-star cohort, focus on odour control being inconsistent and on the general finish. The grey plastic reads as utilitarian next to the appliance styling of the OGO Origin, and in a finished van interior that shows.

Who it suits and who it does not

It suits short cross-country trips, overlanding, and van builders who want more capacity than a small portable without a fixed install. It also suits anyone who wants a unit rated for higher loads than a typical portable.

It does not suit full-time living, and it does not suit anyone whose main worry is odour, because that is the specific area owners report as inconsistent. If smell is your top concern, choose a fixed unit with a vent fan instead.

7. TROBOLO WandaGO – Adjustable Seat Solves the Low-Seat Complaint

Seat height is the most underrated specification in this whole category, and the WandaGO is the only unit that treats it as a design feature. The seat sets to either 12.0 inches or 17.2 inches, which is the difference between crouching and sitting properly on the first morning of a trip.

The rest of the package is well judged for van use. At 10 lb it disappears into a storage locker. The 1.7 gallon solids container and 1.2 gallon liquids container give you 10 to 20 uses for urination and 8 to 12 for defecation per fill, and the SafeShell system is designed to keep the two streams apart.

The built-in urine level indicator

This is the feature I would not want to live without. A visible indicator removes the need to lift the container and check it in front of people, which is the single most unpleasant part of any portable toilet routine.

It also pairs naturally with the 75 percent rule. Check the indicator when you shower, and empty the liquids container before it is full, because a full 1.2 gallon container is heavy and awkward to pour.

Where owners disagree

Odour is the split point. Several owners use cedar chips successfully and report no smell, while a minority report persistent odour even when the contents are covered. The container geometry, a square urine receptacle, is also described as awkward to empty.

Two mechanical details are worth knowing before you buy. The lid can lift the seat ring with it, and urine can end up in or on the bag if the seat is not seated correctly. Both are handling habits rather than defects, but you should know about them.

Who it suits and who it does not

It suits taller users and anyone who finds low portable seats uncomfortable, which forum complaints suggest is a large group. It also suits van builders with a storage locker, because 10 lb is easy to stow out of sight.

It does not suit anyone who needs a large capacity between emptyings, and I would not choose it as the sole toilet for a long trip if odour is your top worry. For a standard-height user who is odour-sensitive, the Nature’s Head or the Cuddy Lite is the better call.

8. Cuddy Lite – Discreet Flush-Fit Install With an LED Full Indicator

The Cuddy Lite solves a problem the rest of the category ignores: how the toilet looks in a finished van. It installs flush with the cabinetry or freestanding, and the solids cover closes the bowl so it does not read as a toilet from the doorway when nobody is using it.

It is listed at 12.3 kg, which works out to about 27 lb, and measures 17 by 15.2 by 16.5 inches. That is a mid-size footprint, deeper than the OGO Origin but considerably shallower than the Separett Villa.

The LED full indicator and the two-plate drop zone

Liquids are diverted by a two-plate cover with an extra-large drop zone, which reduces the misses that cause odour in any separating toilet. The LED indicator for the liquid container runs off a standard 9V battery, so you know when to empty without lifting anything.

Owners consistently name the indicator and the solids cover as the reasons they bought it. Vented owners report no odour, and one notes that two people can go two days before dumping the liquid, which is a useful calibration figure.

What the small review base means for you

At 22 reviews, this is the thinnest data in the roundup, and I would weight the owner enthusiasm accordingly. Ninety percent of reviews are four stars or better, which is encouraging, but 22 reviews does not tell you how a seals and gaskets age over five years.

Two practical gaps to plan for. The 9V battery and the internal fan plug are not in the box, and there are no side handles as standard, so the unit is lifted awkwardly. Condensation can also form at the bottom if you do not vent it, which is why the vent run matters even though core operation needs no electricity.

Who it suits and who it does not

It suits finished van interiors where appearance matters, builders with a sofa base or cabinet run, and anyone who hates guessing when a liquids container is full. Cleaning is straightforward too, with owners reporting a vinegar spray is enough.

It does not suit buyers who want a long record of long-term ownership, or anyone who needs a large capacity between emptyings. With 27 lb and a 17 inch depth, it also needs a real install position rather than a corner.

Will These Composting Toilets Actually Fit in Your Van?

Fit is the question every van-specific roundup should answer first, and almost none of them do. Here are the four standard nooks and what actually goes in each one.

The wet-bath cubicle. Usually around 20 to 26 inches deep. This is the only nook that comfortably takes the Nature’s Head at 20.98 inches or the Cuddy Lite at 17 inches. The OGO Origin at 15 by 16 inches fits anything, and the Separett Villa at 26.5 inches deep will only fit if you build the cubicle around it.

The wheel arch corner. Usually shallow and awkward, often 12 to 15 inches of usable depth. This is OGO Origin territory, and the 15 by 16 inch footprint is the reason it exists. Expect to lose some of the arch space to the unit.

Under a galley or sofa base. Depth is generous, height is not. The Cuddy Lite at 16.5 inches high is the tallest unit likely to fit under a standard base, and the Nature’s Head at 20.98 inches high will not fit under most of them.

A storage locker for a portable. Weight matters more than footprint here. Anything under 12 lb, which covers the WandaGO, the Nomad, the Evo S and the BOXIO, can be lifted into a high van by one person. Anything at 27 lb or above needs two.

One more measurement people forget: check the vent exit before you order a fixed unit. A 2 inch vent hose through a high-roof van wall is a long run, and every 90 degree elbow reduces the airflow the fan can pull.

How to Choose: A Buying Guide for Camper Vans

These are the decisions that actually determine whether you are happy with the unit, in the order I would make them.

1. Match capacity to party size and trip length

Capacity is quoted in uses, and a use is a use, but a household of two generates very different numbers than a solo traveller. The rule of thumb from owner reports is that a fixed unit with a four to six week interval suits two full-time users, while a portable with 8 to 10 uses covers a weekend.

Do the arithmetic on your actual trip before you order. A family of four halves the interval of every number in this article, and that is the calculation most people get wrong.

2. Decide whether the unit is fixed or portable

A fixed unit means cutting a cubicle, running a vent, and wiring 12V power. In exchange you get weeks between emptyings and a fixture that belongs to the van. A portable means no install, no hole in the body, and a much smaller capacity.

Forum research shows owners often cycle up through the options. A Project Van Life poster tried a homemade compostable toilet, a 5 gallon bucket and a portable unit before landing on a fixed self-contained model. That path is a legitimate one, and starting portable is a sensible way to find out what you actually tolerate.

3. Work out your 12V power budget

Only two models here need power: the OGO Origin, with its 12V electric agitator and fan, and the Cuddy Lite’s optional fan and LED. Everything else runs without it.

Add up the fan and agitator draw, the fridge, lighting and water pump, then divide by your solar input. On a small 30 to 40 amp hour lithium auxiliary bank, a weekend is tight once a fridge is running. This is where a composting toilet quietly becomes an energy project rather than a sanitation decision.

4. Choose your composting medium deliberately

Coconut coir leads for good reasons. It absorbs moisture without collapsing, it is light, and it is widely available. Peat moss is cheaper and works well; the r/VanLife owner reporting six to eight months from one bag is a realistic figure, though it varies with use. Hemp bedding is clean and absorbent. Wood shavings are the cheapest but the least absorbent.

The one rule that matters more than the choice is balance. Too dry and solids do not break down. Too wet and odour appears. Every unit here manages this differently, and the fixed units with fans do it more consistently than the portables.

5. Plan for the vent run before you cut anything

Fixed units with a fan need a vent exit. The common mistake is a long run with two 90 degree elbows, which chokes airflow and is a leading cause of the odour complaints in owner threads. Straight runs beat elbowed runs every time.

Plan the exit through a floor, wheel arch, side wall or roof, and seal it properly. An unsealed visible hole in a finished van is the deal-breaker that stops many builds entirely.

6. Think about the emptying end of the cycle

Ask yourself what happens when the container is full and you are parked somewhere awkward. A bag that goes in a household bin is trivial. A fixed unit with a removable bin is a five minute job. A unit that has to be carried out of a wet bath in the dark is not.

The spider handle on the Nature’s Head and the removable, bag-linable bin on the Cuddy Lite are both answers to this question, and both were clearly designed with it in mind.

7. Winter draining, if you travel in cold climates

Liquids freezing in a parked van is the deal-breaker forum owners raise most often in cold weather. A 1.2 gallon container left full overnight below freezing will freeze solid, and the damage to some plastics is permanent.

Two habits solve it. Never leave liquids in the unit overnight in winter; empty it after your last use. And if the van sits unheated for days, drain the container completely rather than topping it up on arrival.

8. Composting toilet vs cassette vs bucket vs portable

Sometimes a composting toilet is the wrong answer, and the honest comparison matters. A chemical cassette toilet is lighter and simpler but needs dump stations or refills, and it carries the porta-potty smell that van owners most want to avoid. A bucket system is free and weighs nothing but has a poor ergonomics story and no odour control. A cassette unit suits people who camp at serviced sites often. A composting toilet suits people who want to go where the services are not.

Maintenance and Emptying Schedule for Two People on the Road

Realistic intervals matter more than any feature, because the unit that gets neglected is the unit that starts to smell.

Daily. Agitate the solids after each use, which on a crank or button unit takes seconds. Check the liquids container at your evening wash routine rather than in the morning. Add medium to top up the solids bin when the level drops below two thirds.

Weekly. Check the solids bin against its rated capacity. For a portable unit this is the emptying point. For a fixed unit rated at four to six weeks, a weekly glance is enough.

Monthly. Empty a full-capacity fixed unit. Inspect the bag liner, the seal and the fan for debris. Wipe the separating funnel, which is the single most common source of odour that gets blamed on the medium.

Yearly. Replace the fan if it has slowed, and check the carbon filter if your unit has one. Inspect gaskets and seals. Re-read the emptying procedure, because the one you read at install is not always the one you are doing.

The rule that keeps everything working: empty before you think you need to. A container emptied at 75 percent is a two minute job with no pressure release. One emptied when it is completely full is an unpleasant job that people avoid, and the avoidance is what creates odour.

When Not to Buy a Composting Toilet in a Van

I would talk you out of a composting toilet in several honest situations, and a roundup that never does is just a sales page.

You camp at serviced sites most nights. A cassette toilet or a site toilet beats carrying a dry-collection system.

Your build is not finished. Cutting a cubicle and a vent exit before the layout stops moving is the most common expensive mistake in van sanitation.

You cannot lift 28 lb into a high roof. This is not a small problem. Below 12 lb, one person can do it alone. Above 25 lb, you need a second pair of hands every time you change vehicles.

You are winter vanlifing and park unheated. Frozen liquids are a genuine failure mode, not an inconvenience.

You need to empty less than weekly for two people. Only the fixed units in this roundup deliver that, and they are the ones that cost you install effort.

Your aversion is stronger than the benefit. A toilet you are uneasy about becomes a toilet you avoid using, which solves nothing.

And one honest technical note. Nothing composts in a van-sized container. What you are buying is a urine-diverting dry-collection system that keeps solids dry with medium and then goes in the bin. Understanding that removes a lot of pressure and a lot of disappointment.

Frequently Asked Questions

Which Composting Toilet Fits Your Van Best?

If you prioritise the longest gap between emptyings and you have a cubicle, the Nature’s Head Spider Handle is the pick. Two full-time users empty it every four to six weeks, and the five year warranty matches a semi-permanent install.

If your constraint is floor space rather than time, the OGO Origin is the answer at 15 by 16 inches, with a push-button agitator and a 2.4 gallon liquid bottle. Pair it with a battery you have actually sized for the fan and agitator draw.

If you are a weekend camper or want the lightest option, the BOXIO is the best value portable at 11.4 lb, or the OGO Nomad at 12 lb if you want zero power and standard bags. If your main complaint is seat height, the TROBOLO WandaGO is the only unit that adjusts between 12.0 and 17.2 inches.

Whatever you choose, measure the nook, plan the vent exit, and buy the medium before the first trip. Those three steps decide whether the best composting toilets for camper vans become an upgrade to your van or an argument with it. Check the current listing for each unit, and pick the one that matches how far you actually go.