Pet Food Calculator
How much should you actually be feeding? Answer a few questions and get a daily calorie target, the exact portion for your food, and how to split it across meals — with the maths shown in full.
Who are we feeding?
Dogs and cats have genuinely different energy needs.
Work out how much to feed your dog each day. Enter their weight and a few details and you'll get a daily calorie target, the amount to serve for your food, and how to split it across meals.
This calculator is educational and does not replace veterinary advice. Pets with a medical condition, or on a prescription diet, should have portions set by their vet.
How this calculator works
It uses the same maintenance-energy equations vets and veterinary nutritionists work from. First the resting energy requirement — the calories needed just to exist — which scales to the power of 0.75 rather than linearly, because a 40 kg dog does not need twice the calories of a 20 kg one.
That figure is then multiplied by factors for life stage, neuter status, activity and body condition. Growing puppies and kittens need roughly two to three times resting energy; a neutered adult needs far less than most bag charts suggest, which is why so many pets creep up in weight on the "recommended" amount.
Nothing here is an AI guess. It is arithmetic, and every multiplier is shown in the result so you can check it or take it to your vet. Published formulas describe a population average — individual pets vary by around 20% either way, so treat the number as a starting point, weigh in after two to three weeks, and adjust.
When feeding more isn't the answer
A portion change won't fix a medical problem. Speak to a vet if you notice any of these:
- Weight loss despite a normal or increased appetite
- Sudden refusal to eat for more than 24 hours (dogs) or 12 hours (cats)
- Rapid weight gain with no change in food
- Drinking or urinating noticeably more than usual
- Ribs or spine becoming prominent over a few weeks
- Vomiting or diarrhoea that persists after a diet change
Feeding questions owners actually ask
How accurate is this number?
It is a well-established starting point, not a prescription. Published maintenance-energy formulas estimate a population average, and individual pets vary by roughly 20% either side. Feed the suggested amount for two to three weeks, weigh your pet, and adjust.
Why does it ask for weight rather than just breed?
Calories scale with actual bodyweight, not breed. Two Labradors of the same age can differ by 15 kg. Breed size is used here only for meal-frequency and growth advice.
Should I use my pet's current weight or their ideal weight?
Enter current weight. If your pet is overweight the calculator applies a reduction to that figure, which is safer than computing from a goal weight you may not have set with a vet.
The bag says something different. Who is right?
Bag charts are broad bands by weight and usually assume an unneutered, averagely active adult, so they often overfeed. Use the calorie figure here with the kcal/cup printed on your bag.
How fast should weight loss be?
Slowly. Roughly 1–2% of bodyweight per week for dogs and no more than 0.5–1% for cats. Cats losing weight too fast can develop hepatic lipidosis, a serious liver condition — always involve your vet.
Do treats count?
Yes, and they are the usual reason a diet stalls. Treats should stay under 10% of daily calories; the result below shows that ceiling and subtracts it from the meal portion.
Free Pet Health Check
Subscribe and get our printable Pet Symptom Cheatsheet — used by thousands of owners.
No spam. Unsubscribe anytime.