Every toilet gets a score from 0 to 100% built from five factors, which maps onto the 5-point rating shown on the site (a 0% score would be 1.5 stars; a perfect score, 5). Each factor is scored against fixed reference points, not against the other products in the list, so adding a new model never moves another model’s rating. Toilets are grouped by kind, urine-diverting and composting, and each group has its own price and capacity scales.
| Factor | Measures | Weight |
|---|---|---|
| Value | current price | 30% |
| Capacity | uses between emptying and urine bottle size; composting type, full-time household rating | 25% |
| Power | fan and heater draw; no power needed scores full marks | 15% |
| Certification | NSF/ANSI 41 certification | 15% |
| Warranty | warranty length | 15% |
Where the numbers come from
Capacity, power draw, certification, dimensions, warranty and the rest come from the maker’s product page, spec sheet or manual, or the maker’s own copy on its Amazon listing. Prices are checked at Amazon and the maker’s own store, and the lowest is used.
The factors
Value is the current price, on a log scale for each group, so going from $1,000 to $500 counts as much as going from $2,000 to $1,000.
| Group | Scores 0 | Full marks |
|---|---|---|
| Urine-diverting | $1,400 | $500 |
| Composting | $3,000 | $1,200 |
Capacity is how much the toilet handles between emptying. For a urine-diverting toilet it’s the maker’s number of uses per solids bin, 40 (zero) to 120 (full), for 70%, and the urine bottle, 0.5 gal (zero) to 2.5 gal (full), for 30%; a toilet that can drain urine to a line gets the full 30%. For a composting toilet it’s the maker’s rating for full-time residents: 1 person scores zero and 6 people full marks.
Power is the running draw of the fan and heater together, on a log scale from 300 W (zero) to 1 W (full). A toilet that needs no power gets full marks. Low draw matters most on solar and batteries.
Certification is full marks for a toilet certified to NSF/ANSI 41, the standard for composting toilets that many health departments and building inspectors ask for, and zero for one that isn’t.
Warranty is the length of the warranty: 1 year scores zero and 5 years full marks.
What isn’t scored
Seat height, size, weight, vent size, material, agitator cranks and looks are listed but not scored. Fit matters most: measure the space, including room to lift out the bin, and check what your local health department allows before comparing scores. Independent tests are listed where they exist, but there are too few to score.
Missing data
If a figure isn’t published, that factor gets the neutral middle score (50) and the product page marks it as estimated.
Ties and discontinued models
Products are ranked by score within each group. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.