How many calories does a dog need per day? The answer depends on its weight, its age, and how active it is — and the way to work it out is resting energy requirement, or RER: RER equals 70 times body weight in kilograms to the power 0.75, and daily calories are RER multiplied by a factor for the dog's life stage. This guide is the dog calorie calculator in words: the formula, the factors, the worked examples, and how to use the result — including treats, weight loss, and weight gain. Every figure is an estimate, not a prescription: individual dogs vary, and the vet's advice matters more than the formula. The dog calorie calculator does the same calculation for your dog's exact weight and stage.
The short version is: weigh your dog, work out its RER, multiply by the factor for its stage, and you have its daily calories. A neutered adult dog needs about 1.6 times RER, and an intact adult about 1.8 times. A puppy needs about 2 times RER, and a puppy under four months about 3 times. A senior needs less: about 1.2 to 1.4 times RER. The dog food calculator guide gives the same method with the food amounts in cups and grams, and the dog food portion calculator guide gives the portion sizes.
The dog calorie calculator formula
The formula is: RER equals 70 times body weight in kilograms to the power 0.75, and daily calories equal RER multiplied by a factor. The factor is about 1.6 for a neutered adult dog, about 1.8 for an intact adult dog, about 2.0 to 3.0 for an active dog, about 2.0 for a puppy, and 3.0 for a puppy under four months, and about 1.2 to 1.4 for a senior. A lactating dog needs about 2 to 4 times RER, depending on the size of the litter.
| Body weight | Neutered adult (x1.6) | Intact adult (x1.8) | Active dog (x2.2) | Senior / weight loss (x1.3) |
|---|---|---|---|---|
| 5 kg | 375 | 420 | 515 | 305 |
| 10 kg | 630 | 710 | 865 | 510 |
| 15 kg | 855 | 960 | 1175 | 695 |
| 20 kg | 1060 | 1190 | 1455 | 860 |
| 25 kg | 1250 | 1410 | 1720 | 1015 |
| 30 kg | 1435 | 1615 | 1975 | 1165 |
| 40 kg | 1780 | 2005 | 2450 | 1445 |
Read the table from top to bottom and the pattern is clear: a dog's calorie needs rise with weight, but not in proportion — a dog that is twice as heavy does not need twice as many calories, because RER grows with weight to the power 0.75. A 5 kg dog needs about 375 kcal a day as a neutered adult, a 10 kg dog needs about 630 kcal, and a 20 kg dog needs about 1060 kcal. The dog calorie calculator works out the exact figure for any weight and stage.
Worked examples
A 10 kg neutered adult dog: RER is 70 times 10 to the power 0.75, which is about 394 kcal, and daily calories are 394 times 1.6, which is about 630 kcal a day. A 25 kg neutered adult dog: RER is about 783 kcal, and daily calories are about 1,253 kcal a day. A 5 kg neutered adult dog: RER is about 234 kcal, and daily calories are about 375 kcal a day.
To work out your own dog's needs, weigh it, look up its RER in the table above, and multiply by the factor for its stage. If your dog is between two weights in the table, take the nearer one — the formula is an estimate, and a few percent either way does not change the result much. The how much food should a puppy eat guide gives the calorie tables for young dogs, and the senior dog diet guide covers feeding in the senior years.
Treats, weight loss, and weight gain
Treats count: a treat is food, and it counts towards the daily calories. A good rule is that treats should be no more than a tenth of the daily calories — so a dog that needs 630 kcal a day should get no more than about 63 kcal of treats, and a dog that needs 237 kcal a day should get no more than about 24 kcal of treats. A biscuit, a chew, and a handful of training treats add up fast, and a dog that gets a lot of treats needs less of its main food, or it will gain weight.
For weight loss, feed for the target weight, not the current weight: work out RER at the target weight, multiply by about 1.0, and aim to lose about 1 percent of body weight per month for a dog and about 0.5 to 1 percent per month for a cat. For weight gain, increase the food by about a tenth and re-check in two weeks. A dog that is losing weight on the calculated amount needs more food, and a dog that is gaining weight needs less — the scales and the body condition score matter more than the formula. The dog weight loss diet plan guide covers a dog that needs to lose weight, and the how to help a dog gain weight safely guide covers a dog that needs to gain weight.
When the calculator is wrong
The calculator is wrong when the dog's weight is wrong, when the factor is wrong, or when the food's calories are wrong. Weigh your dog every month, and re-check the amount every two weeks as a young animal grows. Use the right factor: a neutered adult needs less than an intact adult, a senior needs less than a young adult, and a very active dog needs more than a couch potato. Check the bag for the food's calories, and weigh the food — do not guess with a cup.
The calculator is also wrong when the dog is ill, pregnant, nursing, or recovering from surgery: a pregnant dog needs more food in the last weeks, a nursing dog needs much more, and a sick dog may need a special diet. A dog that is losing weight on the calculated amount needs more food, and a dog that is gaining weight needs less — the scales and the body condition score matter more than the formula. The feeding a pregnant dog guide covers feeding in pregnancy, and the feeding a nursing dog guide covers feeding while nursing.
How to use the calculator
Use the calculator to get a starting point, then adjust by the scales and by feel: weigh your dog every month, feel its ribs and waist, and keep it at a body condition score of 4 or 5 out of 9. If your dog is gaining weight, reduce the food by a tenth and re-check in a month. If it is losing weight, increase the food by a tenth and re-check in a month. A dog that is at a healthy weight, eating a measured amount, and exercised every day, is a dog that will live longer and feel better.
Use the calculator to check the bag, too: if the bag says to feed much more than the calculator says, the bag is probably wrong for your dog — feeding guides on bags are often generous, because they are written for active dogs and because the maker wants you to buy more food. Trust the calculator, the scales, and your vet, not the bag. The dog calorie calculator works out the exact figure for any weight and stage, and the dog food calculator guide gives the same method with the food amounts in cups and grams.
For related reading, see the dog calorie calculator, the dog food calculator guide, the dog food portion calculator guide, the how much food should a puppy eat guide, the senior dog diet guide, the dog weight loss diet plan guide.
Frequently asked questions
How many calories does a dog need per day?
It depends on its weight, its age, and how active it is. Work out its RER — 70 times body weight in kilograms to the power 0.75 — and multiply by a factor: about 1.6 for a neutered adult dog, 1.8 for an intact adult, 2.0 to 3.0 for an active dog, 2.0 for a puppy, and 1.2 to 1.4 for a senior. The table above gives the figures by weight.
What is RER?
RER is resting energy requirement: the calories a dog needs at rest, in a comfortable temperature, doing nothing. It is 70 times body weight in kilograms to the power 0.75. Daily calories are RER multiplied by a factor for the dog's life stage — about 1.6 for a neutered adult dog, or 1.2 for a neutered indoor cat.
How many calories should a 10 kg dog eat?
A 10 kg neutered adult dog needs about 630 kcal a day. Check the bag for the food's calories, and weigh the food.
Do treats count towards daily calories?
Yes — a treat is food, and it counts. Treats should be no more than a tenth of the daily calories. A biscuit, a chew, and a handful of training treats add up fast, and a dog that gets a lot of treats needs less of its main food, or it will gain weight.
How many calories does a dog need to lose weight?
Feed for the target weight, not the current weight: work out RER at the target weight, multiply by about 1.0, and aim to lose about 1 percent of body weight per month for a dog and about 0.5 to 1 percent per month for a cat. Weigh your dog every month, and adjust the food by a tenth at a time.
When should I ask a vet about calories?
Ask your vet if your dog is losing or gaining weight on the calculated amount, if it is pregnant, nursing, ill, or recovering from surgery, or if it has a health condition that affects its diet. A vet can work out the exact amount for your individual dog, and can advise on a special diet if it needs one.
Results on this page are estimates for general information only and are not veterinary advice. If your pet is ill, underweight, overweight, pregnant, or has a health condition, consult your veterinarian before changing diet or care.