Best Portable Cassette Toilets for Vans in 2026
The best portable cassette toilets for vans in 2026: Thetford Porta Potti and Kohree models compared on fresh and waste tank size, flush type and footprint.
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The Thetford Porta Potti 365 is the pick: a piston-pump flush, a 4 gallon fresh tank and a 5.5 gallon detachable waste tank (per its title). For a bigger waste tank for less money, the Kohree KR3124 lists 5.8 gallons of waste and 3.2 gallons of fresh water (per the Amazon listing).
Thetford says its waste indicator shows when to empty after about 27 to 33 flushes, depending on the model. Picks were chosen on tank sizes, flush type and seller.
Our top picks at a glance
1. Best overall
Porta Potti 365Fresh: 4 gal · Waste: 5.5 gal · Flush: Piston pump · Seller: Third party
2. Best value
Kohree KR3124 Cassette Toilet (5.8 gal)Fresh: 3.2 gal · Waste: 5.8 gal · Flush: Not stated · Seller: Kohree
3. Largest tanks
Kohree 6.34 Gal Portable ToiletFresh: 5.3 gal · Waste: 6.34 gal · Flush: Not stated · Seller: Kohree
4. Best small
Porta Potti 135Fresh: Not stated · Waste: Not stated · Flush: Not stated · Seller: Amazon
5. Best curved design
Porta Potti 565E CurveFresh: 4 gal · Waste: 5.5 gal · Flush: Not stated · Seller: Third party
| Pick | Fresh | Waste | Flush | Seller | Buy |
|---|---|---|---|---|---|
| Porta Potti 365Best overall | 4 gal | 5.5 gal | Piston pump | Third party | Amazon |
| Kohree KR3124 Cassette Toilet (5.8 gal)Best value | 3.2 gal | 5.8 gal | Not stated | Kohree | Amazon |
| Kohree 6.34 Gal Portable ToiletLargest tanks | 5.3 gal | 6.34 gal | Not stated | Kohree | Amazon |
| Porta Potti 135Best small | Not stated | Not stated | Not stated | Amazon | Amazon |
| Porta Potti 565E CurveBest curved design | 4 gal | 5.5 gal | Not stated | Third party | Amazon |
Best overall
Porta Potti 365
For most vans.
- Fresh
- 4 gal
- Waste
- 5.5 gal
- Flush
- Piston pump
- Seller
- Third party
Pros
- Piston-pump flush per its title
- Well-known parts supply
Cons
- Thetford lists the 320/345/365/550 series as discontinued
Thetford's support page lists the series as discontinued, so buy while stock lasts and check part availability. The same page gives about 56 flushes per fresh tank and 27 to 33 before emptying, depending on the model.
Best value
Kohree KR3124 Cassette Toilet (5.8 gal)
For a larger waste tank.
- Fresh
- 3.2 gal
- Waste
- 5.8 gal
- Flush
- Not stated
- Seller
- Kohree
Pros
- 5.8 gal waste tank (per the Amazon listing)
- Level indicator (per the Amazon listing)
Cons
- Smaller fresh tank
Kohree lists 5.8 gallons of waste and 3.2 gallons of fresh water (per the Amazon listing). The Kohree 5.8 gallon model has the same waste capacity.
Largest tanks
Kohree 6.34 Gal Portable Toilet
For two people between dump stations.
- Fresh
- 5.3 gal
- Waste
- 6.34 gal
- Flush
- Not stated
- Seller
- Kohree
Pros
- 6.34 gal waste, 5.3 gal fresh (per the Amazon listing)
- 450 lb weight capacity (per the Amazon listing)
Cons
- Bigger footprint
Kohree lists 6.34 gallons of waste, 5.3 gallons of fresh water and a 450 lb weight capacity (per the Amazon listing).
Best small
Porta Potti 135
For occasional use.
- Fresh
- Not stated
- Waste
- Not stated
- Flush
- Not stated
- Seller
- Amazon
Pros
- Sold by Amazon
- 3-year warranty (per the Amazon listing)
Cons
- Smaller tanks
The Porta Potti 135 is sold by Amazon with a 3-year warranty (per the Amazon listing). The Porta Potti 345 is 13 x 16.8 x 15 inches (per the Amazon listing).
Best curved design
Porta Potti 565E Curve
For a tighter corner.
- Fresh
- 4 gal
- Waste
- 5.5 gal
- Flush
- Not stated
- Seller
- Third party
Pros
- 4 and 5.5 gal tanks per its title
Cons
- Fewer details in the listing
The 565E Curve lists 4 and 5.5 gallon tanks in its title. The 260P Marine is a marine-labeled model sold by Amazon.
How we chose
We compared tank sizes, flush type and seller. Thetford's support page gives the flush counts: about 56 flushes per fresh tank and about 27 to 33 flushes before the waste indicator says to empty.
What to look for
Waste tank size
Bigger tanks mean fewer trips to a dump station but are heavier to carry: a full 5.5 gallon tank holds about 46 lb if its contents weigh like water, at the USGS's 8.33 lb per gallon.
Cold weather
Thetford says the waste tank will not freeze unless the temperature drops below 0 F.
Cassette or composting
A cassette toilet flushes and needs a place to empty; a composting toilet needs no water. Compare in composting vs cassette toilets and best composting toilets.
Frequently asked questions
What is the best portable toilet for a van?
The Thetford Porta Potti 365 for its piston flush and waste indicator; the Kohree KR3124 for a 5.8 gallon waste tank at a lower price.
How many flushes does a Porta Potti hold?
Thetford says about 56 flushes per fresh tank, and the waste indicator shows when to empty after about 27 to 33 flushes, depending on model.
Where do you empty a cassette toilet?
At an RV dump station or a toilet connected to a sewer, following local rules.
Will a portable toilet freeze?
Thetford says its waste tank will not freeze unless the temperature drops below 0 F.
Is the Porta Potti 365 discontinued?
Thetford's support page lists the 320, 345, 365 and 550 series as discontinued; stock is still sold.
Sources
- Porta Potti 320 / 345 / 365 / 550 support, Thetford
- Facts About Water, U.S. Geological Survey
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