How Many Calories Should My Cat Eat?

Every other result for this question asks you to judge a body-condition score before it will show a number. You can read this table with nothing but a scale. Find your cat's weight, read across, and you have the daily kcal band from all food and extras — not just the dry portion.

Every row is computed with the two equations in the next section; the tool above reproduces any row on demand, and the grams column uses 400 kcal per 100 g. The “full band” column takes the low end of the spayed/neutered range times 0.8 and the high end times 1.2.

Step 1 — resting energy requirement (RER)

RER = 70 × (body weight in kg)0.75

RER is what a cat burns at complete rest — the cost of staying alive, before any activity is added. The same equation is printed as the method on the Association for Pet Obesity Prevention cat calculator (read 2026-10-21) and is the form used in the AAHA 2021 life-stage guidance. A 4.5 kg cat has an RER of 70 × 4.5^0.75 ≈ 216 kcal/day.

Step 2 — the condition factor

daily kcal = RER × condition factor

The factor is a range, not a point:

These three ranges are the same ones used on our Cat Calorie Calculator, which was benchmarked against published reference calculators on 2026-10-20. There is no factor on this page for kittens, pregnant or nursing queens, or cats with a diagnosed condition — none was found with a traceable source in that round, and none is invented here.

Step 3 — the ±20% individual band

full band = (RER × low factor × 0.8) … (RER × high factor × 1.2)

Two healthy cats of the same weight, sex status and activity can differ by 20–30% in what they actually need. The ±20% band is that variation, and it is why a calculator that returns one integer is over-precise. For the 4.5 kg neutered cat: 216 × 1.2 × 0.8 = 207, and 216 × 1.4 × 1.2 = 363.

Step 4 — turning kcal into grams of your food

grams per day = (daily kcal ÷ kcal per 100 g) × 100

A label that prints “4,000 kcal/kg” is the same as 400 kcal per 100 g. Divide the daily kcal by the energy density and multiply by 100 to get the grams to weigh out. For the 4.5 kg cat at the full band: 207 ÷ 400 × 100 … 363 ÷ 400 × 100 = 52–91 g a day, which is 26–45 g per meal at two meals or 17–30 g at three.

Walk through it by hand. Every line comes from the same arithmetic the tool at the top of the page runs.

Steps 2 and 4 are shown rounded; the tool on this page keeps the unrounded RER and band ends, so a number it prints can differ from this table by one kcal.

You will meet a rule of thumb for cats in kcal per pound of body weight. It is easy to check, and it drifts with weight, because the 0.75 exponent means calories per pound fall as the cat gets heavier. Dividing the RER equation by weight in pounds gives a constant times a falling term:

RER per pound = (70 × 0.45359237) ÷ kg0.25 = 31.75 ÷ kg0.25

The same one-pound rule therefore reads about right for a mid-sized cat and over-feeds a large one while under-feeding a small one: 31.75 ÷ 2^0.25 = 26.7 kcal per pound before any factor at 2 kg, and 18.9 at 8 kg. Checking a per-pound figure against the equation is a two-second sanity test you can run on any label claim.

Grams scale inversely with energy density. For the 4.5 kg cat across the full 208–363 kcal band:

Treats belong inside the total, not on top of it: a common veterinary rule of thumb keeps treats and extras to about 10% of the daily calories, which for a 4.5 kg cat is roughly 21–36 kcal of the 208–363 band. Always use the kcal figure printed on your own bag.

Read on 2026-10-21 for this exact question. This is the part of the page that is ours, not a repeat of theirs.

• The Association for Pet Obesity Prevention cat calculator (rank 1) prints its method — “RER = 70 × current kg^0.75” — but refers to a “selected AAHA 2021 reference factor” without printing the numeric values, and asks for five dropdown judgements plus a measured weight before any figure appears. There is no weight-band table on the page.
• The Pet Nutrition Alliance calorie calculator (rank 2) needs a body-condition score on a 1–9 scale, an ideal weight, the cat's current intake and the kcal content of the target food before it returns anything, and states on the page that the tool is designed for veterinary professionals. Its result is one number, with no band and no printed factor values.
• The Reddit thread (rank 3) is 90+ comments of anecdote: no table, no equation, nothing you can recompute.

What is added here: the answer readable with only a scale, the three factor ranges with their numeric values, the ±20% band composed from the factor range, the per-pound drift check, and the grams at five food densities — all from one published equation you can verify by hand.

• It doesn't choose the food. Energy density is an input here, not an output.
• It doesn't cover kittens, pregnancy, or nursing. No factor with a traceable source was found for those life stages, and none is invented.
• It doesn't grade body condition. That is a hands-on assessment; the weight table works without it, but the band it produces is a starting point, not a diagnosis.
• It doesn't model illness. Diabetes, kidney disease, hyperthyroidism and recovery from surgery need a vet, not a calculator.
• It doesn't suggest brands, and it doesn't hide the arithmetic. Every number on this page can be recomputed from the two equations above.