Dog, Cat and Animal Calorie Calculator

Estimate your animal's daily calories, resting energy requirement (RER) and food portions in grams, cups or meals. Includes dogs, cats, rabbits, guinea pigs, ferrets, birds, horses and farm animals.

Who is using this calculator? Vet and nurse mode unlocks the RER coefficient so you can match your clinic's protocol.

Choose the animal

Select the species so the calculator can use the appropriate veterinary energy model.

Enter the details

Add current weight, units, life stage and activity to calculate the daily starting target.

Use your animal's actual weight today.
RER = K × body weight (kg)0.75. The standard interspecies constant is 70. Adjust only if your protocol or textbook uses a different K value. Accepted range 30 to 140.
kg
Weight loss and gain plans are calculated from the target weight, not the current weight.
Daily energy target
0 kcal/day

Turn calories into food portions

Pick a food type for a typical value, or enter the exact calorie figure from the pack for the most accurate result.

How to set your food's calories
On the bag, look for "calorie content" or "ME". It should match the option chosen above.
Example: a 400 g can that provides 380 kcal. Enter 400, choose grams, then 380 kcal.
We recommend weighing food on a kitchen scale. Cups vary a lot between foods and are easy to over-pour.
Feed per day
Per day (cups)
Each meal

These figures are general guides based on standard resting energy and maintenance formulas. Real needs vary with breed, metabolism, health, neuter status, climate, coat and individual differences. Always feed to keep an ideal body condition score, weigh regularly, and speak to your vet before big diet changes, for weight loss plans, or if your animal is unwell, pregnant or nursing. Not a substitute for veterinary advice. By Dr Duncan Houston.

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How this pet calorie calculator works

Select the species, enter current body weight and choose the closest life stage or activity level. The calculator produces a starting daily energy target. For dogs, cats and other companion mammals, it first estimates resting energy requirement and then applies a life-stage factor.

Resting energy requirement formulaRER = 70 × body weight (kg)0.75
Daily or maintenance energy estimateDER / MER = RER × life-stage factor

RER estimates the calories used at rest. Daily energy requirement (DER), commonly called maintenance energy requirement (MER), adjusts that baseline for age, neuter status, activity, growth or weight management. These calculations are starting points rather than a promise from the calorie gods: two animals of the same weight can still have different needs.

Dog calorie calculator

The dog calorie calculator applies commonly used canine maintenance factors to RER. A healthy neutered adult dog starts at approximately 1.6 × RER, while puppies and working dogs need more. A 10 kg neutered adult dog, for example, has an estimated RER of 394 kcal and an initial maintenance target of about 630 kcal per day.

Common daily energy factors used for dogs
Dog life stageStarting factor
Neutered adult1.6 × RER
Entire adult1.8 × RER
Obesity-prone adult1.4 × RER
Puppy under 4 months3.0 × RER
Puppy over 4 months2.0 × RER

Cat calorie calculator

The cat calorie calculator accounts for lower typical maintenance factors in many indoor and neutered cats. A healthy neutered adult cat starts at approximately 1.2 × RER. For example, a 4 kg neutered adult cat has an estimated RER of 198 kcal and an initial target of about 238 kcal per day. Monitor cats carefully because relatively small daily differences add up quickly.

Common daily energy factors used for cats
Cat life stageStarting factor
Neutered adult1.2 × RER
Entire adult1.4 × RER
Indoor or obesity-prone adult1.0 × RER
Kitten under 4 months2.5 × RER
Kitten from 4 months to 1 year2.0 × RER

Calories and feeding estimates for other animals

The calculator also includes ferrets, rabbits, guinea pigs, birds, horses, cattle, sheep, goats and pigs. Their outputs use species-specific energy or dry-matter models where available. Requirements vary more with species, production stage, environment and diet quality, so use these results as broad planning estimates. A veterinarian or qualified animal nutritionist should formulate diets for growing, breeding, lactating, working or medically unwell animals.

Convert calories into grams, cups or meals

For the most accurate pet food calculation, enter the metabolizable energy (ME) or calorie content printed on the food label. If the label gives kcal per kilogram, the daily food amount is calculated as:

Food portion formulagrams per day = daily kcal ÷ kcal per gram
  • Use a kitchen scale and measure food in grams whenever possible.
  • Include treats, chews, toppers and dental products in the daily total.
  • Keep non-complete treats to a small part of the calorie allowance so the main diet remains balanced.
  • Recheck weight and body condition regularly, then adjust the amount gradually.

Pet calorie calculator FAQs

How many calories should my dog eat each day?

The answer depends on ideal weight, age, neuter status, activity and health. Use the calculated value as a starting point, then monitor weight and body condition and adjust with your veterinarian.

How many calories should my cat eat each day?

Indoor and neutered cats often require fewer calories than active or growing cats. Measure the full daily allowance, including treats, and track weight regularly.

What do RER, DER and MER mean?

RER means resting energy requirement. DER is daily energy requirement, while MER is maintenance energy requirement. Feeding guides may use DER and MER slightly differently, but both adjust baseline energy for the animal's circumstances.

Should I feed by cups or grams?

Use grams whenever possible. Cup estimates vary because food density and kibble shape differ, making accidental overfeeding surprisingly easy.

Can I use this calculator for pet weight loss?

Yes, as an initial estimate when the species offers a weight-loss option. Safe weight loss should use an ideal target weight and veterinary oversight, particularly if your animal has disease or is markedly overweight.

Veterinary review: Reviewed by Dr Duncan Houston, BVSc, veterinarian and founder of ASK A VET™. Last reviewed .

This calculator explains how its estimate is produced and is intended for general feeding guidance. It does not diagnose disease or replace an individual nutritional plan from your veterinarian.

Veterinary nutrition references