The maths, with your numbers
No guesswork and no brand chart. This is the same calculation a vet does on paper, so you can check it.
A healthy adult Ragdoll weighs 15–20 lb (VCA Animal Hospitals cat breed page (quick facts, combined adult range)). Below are daily amounts for that range, for a typical dry cat food (398 kcal per cup, the middle of the cat foods in our list). For your own food, use the calculator above: it is already set to a Ragdoll weight.
| Weight | Lazy indoor | Spayed or neutered | Intact |
|---|---|---|---|
| 15 lb 6.8 kg | ¾ cup81 g · 295 kcal | ⅞ cup97 g · 354 kcal | 1 cup113 g · 413 kcal |
| 20 lb 9.1 kg | ⅞ cup100 g · 366 kcal | 1 ⅛ cups120 g · 439 kcal | 1 ¼ cups140 g · 512 kcal |
Daily totals with no treats. Worked out from resting energy (70 × kg0.75) and the AAHA 2021 life-stage factors. Weight source note: VCA quick facts 15-20 lb; VCA text: males can tip the scale up to 20 pounds.
Good to know
Most cats are spayed or neutered and live indoors, so the middle column is the usual starting point. Many cats eat some wet food too; tick “Mix with a second food” in the calculator to split the day between wet and dry.