
CASTA DIVA CD-W001Casta Diva Elongated One-Piece ADA Toilet
Lowest full flush volume at 1 gpf, with ADA height and a MaP score of 1000 g.
- Flush type
- Pressure-assisted
- Full flush volume
- 1.00 gpf
- Seat height
- 17.2 in
Choosing a toilet comes down to a few tradeoffs. One-piece models are easier to wipe down, while two-piece models split the tank and bowl into separate parts. Flush volume tells you how much water each flush uses. The MaP score tells you how much waste the toilet cleared in a test, so higher is better. Seat height, depth and weight decide fit and comfort. We put 9 products on one spec sheet so you can compare these points side by side.
Quick answer
Ranked from 9 toilets that met our standard, compared on construction, flush type, MAP score.
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Lowest full flush volume at 1 gpf, with ADA height and a MaP score of 1000 g.

Seat height of 21 in, the highest among the four models that list it.

Depth of 26.6 in, the lowest among the six models that list it.
| Spec | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Best Scoreout of 100 | 80 | 74 | 68 | 67 | 56 | 55 | 50 | 45 | 32 |
| Construction | One-piece (best in row) | Two-piece | One-piece (best in row) | One-piece (best in row) | Two-piece | One-piece (best in row) | One-piece (best in row) | Two-piece | One-piece (best in row) |
| Seat heightin | 17.2 in | 21.0 in (best in row) | 17.3 in | 17.0 in | — | — | — | — | — |
| ADA chair height | Yes | Yes | Yes | Yes | Yes | — | — | Yes | — |
| Bowl shape | Elongated (best in row) | Elongated (best in row) | Elongated (best in row) | Elongated (best in row) | Elongated (best in row) | — | Round | Elongated (best in row) | Elongated (best in row) |
| Flush type | Pressure-assisted (best in row) | Single flush | Dual flush (best in row) | Dual flush (best in row) | — | Dual flush (best in row) | Dual flush (best in row) | — | Dual flush (best in row) |
| Full flush volumegpf | 1.00 gpf (best in row) | 1.28 gpf | 1.60 gpf | 1.60 gpf | 1.60 gpf | 1.28 gpf | 1.60 gpf | 1.28 gpf | 1.60 gpf |
| MaP flush scoreg | 1000 g (best in row) | 1000 g (best in row) | 1000 g (best in row) | 1000 g (best in row) | — | 1000 g (best in row) | — | — | 800 g |
| Rough-inin | 12 in | 12 in | 12 in | 12 in | 12 in | 12 in | 12 in | 12 in | 12 in |
| Depthin | 26.9 in | 29.3 in | 26.6 in (best in row) | 27.2 in | 28.4 in | — | — | — | 28.8 in |
| Weightlb | 96.0 lb | 94.0 lb | 99.2 lb | 110.0 lb | 94.0 lb | 84.0 lb | 78.0 lb (best in row) | 96.0 lb | 101.0 lb |
| Soft-close seat included | Yes (best in row) | Yes (best in row) | Yes (best in row) | Yes (best in row) | No | — | Yes (best in row) | No | Yes (best in row) |
| WaterSense certified | Yes | — | — | Yes | — | — | — | Yes | Yes |
| Warrantyyears | 1 year | 2 years (best in row) | 1 year | 1 year | — | 1 year | 1 year | — | 1 year |
We reviewed 10 toilets and kept only the 9 that pass every check below. Those are ranked by a Best Score built from spec fit for this job, sales rank.
These reviews are based on specifications and listing information from the makers and sellers. They cover the top five products in our ranking.
Pressure-assisted one-piece that leads our ranking
This Casta Diva one-piece toilet leads our ranking. It uses a pressure-assisted flush at a full flush volume of 1 gpf. That is the lowest on the page, so it uses the least water per flush among all nine products. The MaP score is 1000 g, which matches the top score listed. The listing says air pressure helps it flush even in low-pressure environments.
Seat height is 17.2 in and the toilet meets ADA chair height. That makes sitting down and standing up easier for many adults. The listing says the flush can run by foot kick or side button. It needs no electricity. The rough-in is 12 in, so check your floor plumbing before you buy.
At 96 lb, it is heavy, so plan for two people on delivery day. Depth is 26.9 in, among the shorter depths for models that list it. The warranty is 1 year, the same as most models that list one. A soft-close seat is included.
VerdictA strong all-round pick for accessible height and low water use.
A 21 in tall two-piece for easier sitting
The HT-140 sits at 21 in, the highest seat height among the four models that list it. A taller seat reduces how far you lower yourself, which can help people with mobility issues. It is also marked ADA chair height. The elongated bowl adds room. That height suits seniors, as the listing notes.
Flush performance is listed at a MaP score of 1000 g, tied for the top score. It uses a single flush at 1.28 gpf. That is lower than the 1.6 gpf on five other models, but above the 1 gpf pressure-assisted unit that leads our ranking. There is no dual-flush option.
It is a two-piece design, so the tank and bowl are separate parts. At 29.3 in deep, it is the deepest among models that list depth, so measure your bathroom first. It weighs 94 lb. The warranty is 2 years, the longest listed here. The listing also notes a 12 in rough-in.
VerdictBest for buyers who want maximum seat height and the longest warranty.
Compact dual-flush one-piece with the shortest depth
The HOROW T0338W is a one-piece toilet with the shortest depth among models that list it, 26.6 in. That helps in small bathrooms where floor space is tight. The elongated bowl keeps seating comfortable. Seat height is 17.3 in and it meets ADA chair height, so standing up takes less effort for many adults.
It offers dual flush at 1.1 and 1.6 gpf. Use the lower volume for liquids and the higher one for solids to save water. Dual-flush systems let you pick a smaller flush when a full one is not needed. The listed full flush volume is 1.6 gpf, and the MaP score is 1000 g. The listing mentions a fully glazed 2 in trapway meant to move waste through.
This model weighs 99.2 lb, so installation takes two people. It has a 12 in rough-in, and the listing says a 10 in version also exists. The warranty is 1 year. A soft-close seat is included. The data does not show WaterSense certification, so check first if that matters to you.
VerdictA compact, accessible-height pick that ranks third on our list.
Heaviest one-piece here, with WaterSense and dual flush
The CD-T005 is the heaviest toilet on the page at 110 lb. Plan for two people to lift it into place. It is a one-piece with an elongated bowl, and the listing describes a skirted design that is easier to wipe down. The tank and bowl are one unit, so there is no tank seam.
Seat height is 17 in, the lowest among the four models that list it, but it still meets ADA chair height. Flush is dual at 1.1 and 1.6 gpf, with a MaP score of 1000 g. It is WaterSense certified. The full flush uses 1.6 gpf, more than the 1 gpf of the pressure-assisted leader.
The rough-in is 12 in and depth is 27.17 in. A soft-close, quick-release seat is included. The listing says it includes a wax seal and the hardware needed to install it. The warranty is 1 year, in line with most models that list one. Treat the weight as a delivery and installation issue, not a performance one.
VerdictA capable dual-flush model, held back only by weight and a 1-year warranty.
TOTO Drake: a two-piece with fewer published specs
The TOTO Drake CST776CSFG is a two-piece toilet with an elongated bowl. It is marked ADA chair height, and the listing calls it Universal Height, which is taller than a standard toilet. The maker does not publish an exact seat height in this data, so check the exact height before you buy if fit matters.
The flush uses 1.6 gpf. The listing describes a Tornado Flush that swirls water around the bowl, a 3 in flush valve and a siphon jet bowl. No MaP score is listed, so waste removal cannot be compared with the others. The trap seal is listed at 2-1/8 in.
The soft-close seat is not included. The listing offers a TOTO SoftClose seat as an add-on. The wax ring, flange bolts and water supply lines are also bought separately. It weighs 94 lb, has a 12 in rough-in and is 28.375 in deep. No warranty length is listed.
VerdictA reasonable two-piece, but the thin spec sheet leaves too many gaps for a higher rank.
Best among the reviewed tools
One-piece toilets join the tank and bowl, which leaves fewer seams to clean. Two-piece toilets keep them separate. On this page the one-piece models range from 78 lb to 110 lb, and the two-piece models from 94 lb to 96 lb. Weight matters when you carry and set the toilet.
Full flush volume is the water used per flush, so lower saves water. It ranges from 1 gpf to 1.6 gpf here. MaP score is the grams of waste removed in a test, and 1000 g is the highest listed. Six of nine products list it.
Seat height affects how easy it is to sit and stand. ADA chair height suits many seniors and people with limited mobility. Among the four models that list seat height, the range is 17 in to 21 in. Taller is not always better, so match it to the users.
Rough-in is the distance from the wall to the drain center. Every product here lists a 12 in rough-in. Depth runs from 26.6 in to 29.3 in among the six models that list it. Measure your space, including door swing, before you order.
Neither is better for everyone. One-piece models have a tank joined to the bowl, which gives fewer places for dirt to collect. Two-piece models split into separate parts. Here, the leading product is a one-piece, but two-piece models rank second and fifth.
Lower volume uses less water per flush. The lowest on this page is 1 gpf, and the highest is 1.6 gpf. Dual-flush models with 1.1 and 1.6 gpf options let you use less water for liquids. Check the MaP score too, since a low volume only helps if it clears waste.
ADA chair height is a taller seat that makes sitting and standing easier for many adults. On this page, seat heights run from 17 in to 21 in among the four models that list them. Both TOTO Drake models are marked ADA height without an exact number.
MaP score shows the grams of waste a toilet removed in a flush test. Higher is better. Five products here list 1000 g, the highest, and one lists 800 g. Three products do not list a score, so check the maker's page.
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