Dog and Cat Food Portion Calculator (Calories per Day)
Estimate how many calories your dog or cat needs a day and how many grams of their food that is, using the standard veterinary formulas. Free, private and instant.
How to use the Dog and Cat Food Portion Calculator (Calories per Day)
- Enter your pet’s weight and choose kilograms or pounds.
- Choose the life stage that fits, for example neutered adult dog or weight-loss cat.
- Enter the calories per 100 g from the food label, and the number of meals.
- Read the daily calories and the grams of food, then adjust to your pet’s body condition.
Example
Worked example (20 kg neutered adult dog, food 350 kcal per 100 g, 2 meals)
- Resting energy: 70 × 20^0.75 = 662 kcal
- Daily energy: 662 × 1.6 = 1,059 kcal
- Food a day: 1,059 ÷ 350 × 100 = 303 g, which is 151 g per meal
Limitations
- The formula is an average. Individual needs vary a lot with breed, age, coat and activity.
- Dry food energy is usually printed per 100 g or per kg. Wet food is often lower, so use the right figure for the food you give.
- For weight loss, ask a vet for a safe target, because cutting calories too far is not safe for cats in particular.
- Not veterinary advice.
Sources
Rates and rules last checked against these sources on 2026-10-08.
About this tool
The Pet Food Portion Calculator estimates a dog’s or cat’s daily energy need from weight and life stage. It uses the resting energy requirement, 70 × body weight in kilograms to the power of 0.75, multiplied by a factor for age, neutering and activity, then turns the calories into grams using your food’s energy content. The result is a starting point to adjust by watching body condition, and a vet is the best guide for puppies, kittens, ill or overweight pets.
Also searched for as: how much should I feed my dog, how much to feed a cat, dog calorie calculator, cat calorie calculator, dog food amount by weight, resting energy requirement calculator.
Dog and Cat Food Portion Calculator (Calories per Day) is part of ToolStack Hub's Calculators. It runs entirely in your browser, which keeps your data private and makes results instant. There is nothing to install and no account to create. There is no usage limit.
Frequently asked questions
How many calories does my dog need?
A 20 kg neutered adult dog needs about 1,060 kcal a day by the standard formula. It depends on the dog.
How do I work out how much to feed in grams?
Divide the daily calories by the food’s kcal per 100 g and multiply by 100.
Do treats count?
Yes. Take them off the daily total, ideally keeping treats under about 10% of calories.
Is the Dog and Cat Food Portion Calculator (Calories per Day) free?
Yes. Dog and Cat Food Portion Calculator (Calories per Day) is completely free with no sign-up, limits or watermarks.
Is my data private when I use the Dog and Cat Food Portion Calculator (Calories per Day)?
Yes. It runs in your browser, so your input is not uploaded to our servers.
Does it work on mobile?
Yes. ToolStack Hub tools work on phones, tablets and desktop browsers.
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