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Pet Calorie Calculator

Computes a dog's or cat's resting energy requirement (RER = 70 × kg^0.75) and multiplies it by the life-stage factor used by veterinary nutrition services (e.g. neutered adult dog 1.6, cat 1.2) to give daily maintenance calories.

When to use

You need a starting daily calorie target for a dog or cat from its weight and life stage, e.g. to portion food from the kcal/cup value on the bag.

Do not use when: The animal is pregnant, lactating, doing heavy work or is ill; those needs (2–8 × RER or disease-specific) require veterinary guidance. For people use tdee.

Formula

RER = 70 × weight_kg^0.75; MER = RER × factor (dog: neutered adult 1.6, intact 1.8, inactive 1.3, weight loss 1.0, puppy <4 months 3.0, puppy 4 months–adult 2.0, light work 2.0, moderate work 3.0; cat: neutered 1.2, intact 1.4, inactive 1.0, weight loss 0.8, kitten 2.5)

Factors follow the Ohio State University Veterinary Medical Center table used with the WSAVA nutrition toolkit; the inactive dog factor is the midpoint of the published 1.2–1.4 range. The result is a starting point: weigh the animal every 2–4 weeks and adjust portions by about 10% to hold ideal body condition.

Inputs

ParameterTypeUnitRequiredDescription
speciesenum: dog | catyesDog or cat; selects the factor table.
weight_kgnumberkgyesCurrent body weight in kilograms (use the target weight for a weight-loss plan). Range: ≥ 0.3, ≤ 120
life_stageenum: neutered_adult | intact_adult | inactive_obese_prone | weight_loss | growth_under_4_months | growth_4_months_to_adult | light_work | moderate_workdefault neutered_adultLife stage or activity level; each maps to a multiple of RER.

Outputs

OutputTypeUnitDescription
rer_kcal_per_daynumberkcal/dayRER = 70 × weight_kg^0.75.
mer_factornumberMultiplier applied to RER.
mer_kcal_per_daynumberkcal/dayMaintenance energy requirement = RER × factor.
mer_kj_per_daynumberkJ/daySame requirement in kilojoules (1 kcal = 4.184 kJ).
weight_lbnumberlbBody weight in pounds.

Example

10 kg neutered adult dog: {"species":"dog","weight_kg":10,"life_stage":"neutered_adult"}{"rer_kcal_per_day":394,"mer_factor":1.6,"mer_kcal_per_day":630,"mer_kj_per_day":2635,"weight_lb":22}

4 kg neutered adult cat: {"species":"cat","weight_kg":4,"life_stage":"neutered_adult"}{"rer_kcal_per_day":198,"mer_factor":1.2,"mer_kcal_per_day":238}

GET https://tttkmbb.com/api/v1/calculate/pet-calories?species=dog&weight_kg=10&life_stage=neutered_adult

Machine access

Sources

FAQ

How do I turn calories into cups of food?

Divide the daily calories by the kcal per cup (or per 100 g) printed on the food label; typical dry dog food is 300–400 kcal per cup.

Why is the result lower than the feeding guide on the bag?

Bag guides are often based on intact, active adults (1.8 × RER or more). Neutered, indoor pets need less, which is why many are overweight when fed by the bag.

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