Dog Food Calculator – How Much Should I Feed My Dog?
Bag guidelines cover huge weight bands. This works out your dog's daily calories, then turns them into grams of the food you actually buy.
Only have kcal per 100 g? Multiply it by 10 to get kcal per kg.
Your dog's daily feeding chart
1059 kcal a day
- From meals
- 953 kcal
- Treat allowance (max 10%)
- 106 kcal
- Dry food per day
- 265 g
- Per meal (2 meals)
- 132 g
Weigh food on kitchen scales – scoops vary by up to 30 per cent.
How much food does a dog actually need?
Every feeding calculation starts with resting energy requirement, or RER – the calories a dog burns just staying alive. The formula vets use is 70 multiplied by body weight in kilograms to the power of 0.75. That exponent matters: energy needs don't rise in a straight line with weight, which is why a 40 kg dog needs nowhere near twice the food of a 20 kg dog.
Real life is then layered on top with a multiplier. A neutered adult dog typically needs 1.6 times RER, an intact adult 1.8, and an older or very sedentary dog 1.4. Puppies need far more: 3.0 times RER under four months, dropping to 2.0 between four and twelve months. Working dogs sit anywhere from 2.0 up to 5.0, depending on how hard and how cold the work is.
Worked example: a 20 kg neutered Labrador cross
RER is 70 × 20^0.75, which comes to about 662 kcal. Multiply by 1.6 for a neutered adult and you get roughly 1,060 kcal a day. Holding back ten per cent for treats leaves about 954 kcal for meals. On a dry food with 3,600 kcal per kg, that is 265 g a day, or about 132 g twice a day. If you also feed a wet food at 900 kcal per kg and want a third of the calories from it, you'd feed roughly 177 g of dry and 353 g of wet across the day.
Reading the label properly
Look for "metabolisable energy" on the bag or tin. It may be given per 100 g, per kg or per cup. Per 100 g figures need multiplying by ten to get kcal per kg. Never assume two foods are interchangeable by weight – a light dry food and a performance dry food can differ by over a thousand calories per kilogram.
Weight loss without misery
If your dog needs to slim down, calculate using their ideal weight and the 1.0 multiplier, then aim for one to two per cent of body weight lost per week. Bulk meals out with safe low-calorie vegetables such as green beans or courgette, weigh everything, and swap food-based rewards for play where you can. Weigh your dog every two weeks and adjust by around ten per cent at a time. Any weight loss plan for a dog with a health condition should be agreed with your vet first.
Tips that make a real difference
- Use scales, not scoops. It is the single biggest source of accidental overfeeding.
- Count everything: dental chews, training treats, the crust of toast, the last of the yoghurt.
- Split the daily amount across meals rather than topping the bowl up through the day.
- Re-check the sums whenever your dog is neutered, changes food, or changes routine.
- Score body condition monthly – ribs easy to feel, visible waist from above, tucked tummy from the side.
When to talk to your vet
Calculators assume a healthy dog. Kidney disease, pancreatitis, diabetes, allergies and pregnancy all change what and how much a dog should eat. So does a dog who suddenly won't eat, or one who is losing weight on a normal portion. Those are conversations for your vet, not a website.
Frequently asked questions
How many calories does my dog need a day?
Start with resting energy requirement (70 × weight in kg to the power 0.75) and multiply by a lifestyle factor: 1.6 for a neutered adult, 1.8 intact, 1.4 for an inactive or senior dog, 2.0 for a puppy over four months and up to 5.0 for a hard-working dog.
Should I feed for my dog's current weight or ideal weight?
For weight loss, always use the ideal weight with a factor of 1.0. Feeding for the weight your dog is now simply maintains it.
Where do I find the calories in my dog food?
Look for 'metabolisable energy' on the bag, usually as kcal per 100 g or kcal per kg. If it isn't listed, use our defaults of 3,600 kcal/kg for dry food and 900 kcal/kg for wet.
How many meals a day should my dog have?
Puppies need three to four small meals, adults do well on two. Deep-chested breeds should avoid one large meal and vigorous exercise straight after eating.
How many treats can I give?
No more than ten per cent of daily calories, and take that off the meal amount rather than adding it on top.
Can I mix wet and dry food?
Yes. Decide what share of the calories should come from each, then weigh both. Our mixed feeding option does that split for you.
My dog is always hungry. Am I underfeeding?
Not necessarily – some breeds are always keen. Check body condition: you should feel ribs easily with a flat hand and see a waist from above. If your dog is losing weight or ravenous all the time, see your vet.
How quickly should my dog lose weight?
One to two per cent of body weight a week. Faster than that risks muscle loss, and in some dogs other health problems. Always plan a diet with your vet.
Estimates only – not a substitute for advice from your vet.
Last reviewed: 22 September 2026