Compare daily calorie and food portion requirements between cat breeds. See how a Maine Coon's feeding needs differ from a Siamese or Munchkin based on AAFCO and WSAVA metabolic formulas.
A 5 lb Singapura and a 25 lb Maine Coon do not eat the same -- but even at the same weight, breeds differ in metabolism and frame. The Breed Size Feed Comparison Calculator compares calorie needs across breeds and sizes so you can portion realistically for your cat's build.
Owners of small or large breeds often mis-portion: small breeds get too much (easy keepers gain fast), large breeds get too little relative to their lean mass. Comparing breeds on a level basis prevents both errors.
Calorie need scales with lean body mass, estimated via the RER formula 70 x kg^0.75 -- note the 0.75 exponent means bigger cats need more total calories but fewer per pound than small cats. A 20 lb cat needs more than a 10 lb cat, but not twice as much; per-pound need falls as size rises.
Breed metabolism varies. Lean, active Oriental breeds (Siamese, Bengal, Abyssinian) run hot and may need more calories per pound than stocky, calm breeds (British Shorthair, Persian, Ragdoll) that trend toward obesity. Hairless breeds (Sphynx) burn extra staying warm and often need 1.2-1.5x a coated cat's calories at the same weight.
Frame matters more than the scale number. Two cats both weighing 12 lb can have very different ideal intakes if one is a muscular Bengal and the other a round British Shorthair. Body condition scoring -- not the number alone -- should confirm the portion.
In the Breed Compare calculator, enter your cat's weight and pick a breed class -- large (Maine Coon, Ragdoll, Norwegian Forest) or small (Siamese, Singapura, Devon Rex). The tool shows how absolute needs differ even when per-kilo intensity is similar, and flags breeds prone to over- or under-feeding.
Use actual weight, not the breed 'average' -- individual cats vary more than breed stereotypes.
The breed trap is assuming a big cat automatically needs 'a lot' and a small cat 'a little' without scaling per kilo. Large breeds actually have similar per-kilo needs to small breeds; the difference is absolute, driven by mass. The error is feeding a 20 lb Maine Coon like a 20 lb lazy domestic -- the Maine Coon may be lean-at-weight, not overweight.
Small breeds are easily overfed into obesity because their absolute budget is tiny.
Giant breeds mature slowly. Maine Coons and Norwegian Forest Cats keep growing (and needing growth food) to 18-24 months, so their intake stays high longer than a small breed's. Adjust expectations by breed, not just age.
Small breeds are easy keepers. Singapura, Devon Rex, and similar tiny cats gain quickly on standard portions; measure carefully and favor high-protein food to preserve lean mass. See the adult feeding calculator for the base target.
Breed comparison scales the same RER by mass, then life stage; it does not invent new factors. The insight is that per-kilo need is similar across breeds, so a large breed's bigger absolute number is mostly mass, not metabolism.
RER = 70 x (weight_kg)^0.75 for each cat, then x 1.2 (neutered adult). An 18 lb (8.16 kg) Maine Coon: RER ≈ 338, MER ≈ 406 kcal. A 6 lb (2.72 kg) Siamese: RER ≈ 147, MER ≈ 176 kcal. The big cat needs more absolute kcal, but per kilo (22.5 vs 29.3 kcal/kg) the small cat is actually denser-fed.
Worked example: compare a 12 lb Bengal and a 12 lb British Shorthair, both neutered adults. RER for 12 lb (5.4 kg) = 70 x 5.4^0.75 = about 240 kcal. The Bengal is a lean, high-metabolism breed and may need the upper end (about 1.3-1.4x = 310-340 kcal), while the British Shorthair is a calm, easy-keeper breed that trends toward obesity and may do better near 1.1-1.2x (about 265-290 kcal). Same weight, different targets -- because frame and metabolism differ. A 20 lb Maine Coon (9.1 kg) has RER about 350 kcal and, even at 1.2x, needs about 420 kcal -- more than the small breeds but fewer per pound. Confirm with body condition, not the scale alone. Remember that individual cats vary: a very active Bengal may need more than a couch-potato Bengal, and a Domestic Shorthair of the same weight may fall anywhere on the range. Use breed as a starting assumption, then adjust by body condition. If ribs are hard to feel or the waist disappears, feed for the lower end of the range; if the cat is too lean, feed toward the higher end. The calculator gives you a data-driven baseline, but the cat's body tells you the final answer.
A myth is that a bigger cat simply eats twice a smaller one; because need scales with weight to the 0.75 power, per-pound need falls as size rises. Another is that all small breeds are low-maintenance; tiny easy-keepers like the British Shorthair gain readily and need careful portions. And that breed alone sets the number -- body condition still confirms it, since two same-weight cats can have different frames.
Breed stereotypes are not medical advice. Large breeds can get hip/joint and heart conditions; small breeds can be finicky or hyperthyroid. If a breed-typical cat is losing or gaining despite correct portions, vet-check the condition, not just the bowl. Breed rescues and your vet know the specific risks.
Select two breeds and enter weights to compare their daily calorie and food portion requirements.