Cats in a 2018 crossover study drank 27.5 mL per kg a day from a still bowl and 26.3 and 26.1 from flowing ones: about the same
Our own calculation, 7 November 2026 (UTC), for the article "Do cats drink more from a fountain?". Inputs are the study's own means (Robbins et al. 2018, J Feline Med Surg; 16 healthy laboratory cats fed dry food, 14 completed; P = 0.942 for any difference between bowls): still bowl 27.483 mL per kg a day (spread 5.847), circulating 26.327 (7.342), free-falling 26.137 (6.487). Per-cat amounts are the mean times the cat's weight, computed in millilitres and again in microlitres; the two agree. Rounding is half up from the paper's exact means.
What we found
- A 4 kg cat: 109.9 mL a day from the still bowl (110 mL), 105.3 from the circulating bowl (105 mL), 104.5 from the free-falling bowl (105 mL).
- A 5 kg cat: 131 to 137 mL a day, about 130 to 140 mL, at 26 to 27.5 mL per kg.
- The spread between cats on the still bowl is 21.3% of its mean, about 21%, about a fifth.
- The still bowl's mean is 1.25 mL per kg a day above the average of the two flowing bowls (26.23): about 1.3.
Check it yourself
| Bowl | Mean, mL per kg a day | Spread | For a 4 kg cat | For a 5 kg cat |
|---|---|---|---|---|
| Still | 27.483 (about 27.5) | 5.847 | 109.9 mL (about 110) | 137.4 mL |
| Circulating | 26.327 (about 26.3) | 7.342 | 105.3 mL (about 105) | 131.6 mL |
| Free-falling | 26.137 (about 26.1) | 6.487 | 104.5 mL (about 105) | 130.7 mL |
What this cannot tell you: cats on wet food (they drink less from the bowl), cats with kidney disease, kittens or old cats; your own cat's preference.