Kitten Feeding Calculator
How much to feed a kitten comes down to what it weighs and the fact that it is still growing — a kitten needs roughly twice what an adult cat of the same weight would. The figure below uses the growth factor the Merck Veterinary Manual publishes.
Daily calories
220 kcal
per day — for a 3 lb kitten, using Merck’s growth factor.
How much to feed a kitten
Start from resting needs — 70 × (body weight in kg) raised to the power 0.75 — then multiply by 2.5, the growth factor Merck publishes for kittens. That gives calories a day. To turn it into food, find the kcal per cup or per can on the label — every pet food sold in the United States must declare it — and divide. Treats count toward the same total.
Two sources, and they don’t agree
Merck publishes one flat factor of 2.5 for the whole of kittenhood. FEDIAF publishes three steps instead, falling with age:
| Age | × maintenance |
|---|---|
| Up to 4 months | 2–2.5 |
| 4 to 9 months | 1.75–2 |
| 9 to 12 months | 1.5 |
The two only overlap before 4 months, and only at the very top of FEDIAF’s range. By one year Merck’s figure sits 67% above what FEDIAF publishes. We calculate with Merck — the source this site already uses for cat energy — and show you the gap rather than splitting the difference, because no document publishes a number in between.
One reason not to average them: they aren’t measuring from the same base. FEDIAF computes a cat’s maintenance requirement on body weight to the power 0.67, citing the intra-specific coefficient proposed by Heusner in 1991, while Merck uses 0.75. Those two exponents don’t convert into one another.
Common questions
How much should I feed my kitten?
Start from resting needs — 70 × (body weight in kg) raised to 0.75 — then multiply by 2.5, the growth factor the Merck Veterinary Manual publishes for kittens. That gives calories a day. Look for the kcal per cup or per can on the label — every pet food sold in the United States must declare it — and divide the daily figure by that.
Do other sources give the same answer?
No, and this is the clearest disagreement on the site. Merck publishes one flat factor of 2.5 for the whole of kittenhood. FEDIAF publishes three steps instead: 2–2.5 × up to four months, 1.75–2 × from four to nine months, and 1.5 × from nine to twelve. The two only overlap before four months, and only at the very top of FEDIAF's range. By one year Merck's figure is 67% above what FEDIAF publishes. We calculate with Merck and show you the gap rather than splitting the difference.
Why can’t the two be averaged?
Because they aren't measuring from the same base. FEDIAF computes a cat's maintenance requirement on body weight to the power 0.67, citing the intra-specific coefficient proposed by Heusner in 1991; this calculator follows Merck, which uses 0.75. Those two exponents don't convert into one another, so averaging the multipliers would combine numbers that don't share a starting point.
When does a kitten switch to adult food?
FEDIAF's table runs to twelve months, which is as far as it treats a cat as growing. What to switch to, and when, is a conversation with your veterinarian — the calorie figure here tells you how much, not which food.
How much wet food should I feed a kitten?
The same daily calorie total applies whichever form the food takes; only the density changes. Wet food carries far fewer calories per gram than dry, so the same number of calories is a much larger volume. Find the kcal per can on the label and divide the daily figure by it — treats count toward the same total.
This is a starting estimate, and the two published sources behind it disagree by a wide margin past four months. Merck notes an individual animal can differ by up to 30% either way. Set the amount with a veterinarian.
Verified on . Based on Nutritional Guidelines for Complete and Complementary Pet Food for Cats and Dogs (FEDIAF (European Pet Food Industry Federation), 2025 edition (growth curves Table VII-8a, growth energy VII-8b and VII-10)) and Nutritional Requirements of Small Animals — energy requirements of the dog and cat (Merck Veterinary Manual, “Energy” section, accessed 2026-07-23). See the method.