Dog Food Calculator

Estimate how many calories your dog needs each day and how much wet or dry food that works out to, based on its weight and activity level.

Quick answer: A dog's daily calories come from its resting need — 70 × (weight in kg)^0.75 — multiplied by an activity factor (about 1.6 for a typical neutered adult). Divide that by the calories in the food to get the amount to feed. A 30 lb neutered adult needs roughly 790 kcal a day.

This is a general starting-point estimate, not veterinary advice. Ideal intake varies with breed, age, health and body condition. Check your dog's body condition and ask your vet, especially for puppies, pregnant or nursing dogs, or any dog with a health condition.

Dog's weight

Weight unit

Life stage & activity

Calories in the food

Food measure

How much to feed a dog depends first on how many calories it burns, which is driven by its weight and how active it is. Vets estimate this with the resting energy requirement (RER) and then scale it up for activity to get the maintenance energy requirement (MER). Once you know the daily calories, the amount of food is simply that number divided by the calories in whatever food you use — which is why two foods can need very different portion sizes.

How the calculation works

RER (kcal/day) = 70 × (body weight in kg)^0.75
MER (kcal/day) = RER × activity factor
Amount to feed = MER ÷ calories per unit of food

Typical activity factors are about 1.6 for a neutered adult, 1.8 for an intact adult, 1.0 for weight loss, 2.0–5.0 for very active or working dogs, and 2.0–3.0 for growing puppies. The calories in the food (its metabolisable energy) are on the label, often as "kcal per can", "kcal/kg" or "kcal per cup".

Worked example

A 30 lb dog is 13.6 kg. RER = 70 × 13.6^0.75 ≈ 70 × 7.08 ≈ 496 kcal. For a neutered adult, MER = 496 × 1.6 ≈ 793 kcal a day. If a can of wet food holds 350 kcal, that is 793 ÷ 350 ≈ 2.3 cans a day, best split across two meals.

Adjust for the individual dog

These formulas give a population average; real dogs vary by 20% or more. Weigh your dog, watch its body condition (you should feel the ribs easily but not see them), and adjust the amount over two to three weeks. Treats should stay under 10% of daily calories. Puppies, pregnant and nursing dogs, and dogs recovering from illness have special needs — follow your vet's guidance.

Frequently asked questions

How many calories does my dog need per day?

Roughly 70 × (weight in kg)^0.75 for resting, times an activity factor of about 1.6 for a normal adult. A 30 lb dog needs around 790 kcal a day.

How much wet food should I feed?

Divide the daily calories by the calories per can shown on the label. If your dog needs 790 kcal and a can is 350 kcal, feed about 2.3 cans a day.

How often should I feed my dog?

Most adult dogs do well on two meals a day. Puppies usually need three or four smaller meals.

My dog is gaining weight — what should I change?

Use the weight-loss factor, cut treats, and re-check the portion. Confirm a safe target weight and rate of loss with your vet.

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For general information only — not veterinary advice. Consult your vet for feeding plans, weight management and any dog with special needs.

Written by the CalcPine team · Reviewed for accuracy · Last updated 24 July 2026 · Method: RER = 70 × kg^0.75; MER = RER × activity factor; portion = MER ÷ food calories.