How much should I feed my dog?
This dog food calculator answers the question every owner asks: how many calories does my dog need, and how much of my food is that? It uses the method vets use — a resting energy requirement worked out from body weight, multiplied by a factor for life stage and activity — and then converts the calories into grams and cups using the numbers printed on your own bag or can.
It works for puppies, neutered and intact adults, lazy seniors, working dogs, and dogs on a diet. The factors come from the 2021 American Animal Hospital Association (AAHA) nutrition guidelines and the Merck Veterinary Manual, and every factor is editable, because no formula fits every dog. There are no brand presets: type the calorie content from your food’s label, whichever country you bought it in.
The number you get is a starting point, not a prescription. Dogs of the same weight can differ by up to half in what they burn, so the scale and your hands on your dog’s ribs are the final judge.
How to use the Dog Food Calculator
- Enter your dog’s current weight in kg or lb, or pick a breed to fill in a typical adult weight.
- Choose the life stage and activity. The energy factor fills in automatically with the published range underneath; change it if your vet gave you a different one.
- For weight loss, enter the target weight — calories are then based on that weight, not the current one.
- Type the calorie content from the label (kcal per kg or per 100 g) and, if listed, the kcal per cup.
- Set meals per day and the share of calories you give as treats, then read the grams, cups and grams per meal.
Dog Food Calculator features
Vet formula, shown in full
RER = 70 × weight0.75, then × the life-stage factor, with every step written out so you can check it.
Eleven life stages
From puppies under four months to heavy working dogs, pregnancy and nursing, each with its AAHA or Merck range.
Your food, any label
kcal per kg (US, India) or kcal per 100 g (UK and Europe), plus kcal per cup for scoop feeders.
Treat budget
Reserve a percentage for treats and the main food shrinks to match, so total calories stay the same.
kg or lb
Switch units at any time; your choice is remembered on this device.
The formula and a worked example
Resting energy requirement (RER) is the energy a dog uses lying still in a comfortable room: RER = 70 × body weight in kg0.75 kcal a day. The 0.75 power reflects that small dogs burn more per kilogram than large ones. Daily needs (maintenance energy requirement, MER) are RER × a factor.
Example: a 20 kg neutered adult. 200.75 = 9.457, so RER = 662 kcal. × 1.6 = 1,059 kcal a day. A dry food with 3,600 kcal/kg gives 1,059 ÷ 3,600 × 1,000 = 294 g a day, or 147 g in each of two meals; at 360 kcal per cup that is about 2.9 cups.
Energy factors used
Sources: AAHA 2021 Nutrition and Weight Management Guidelines for Dogs and Cats (“Energy Requirement Calculations”); Merck Veterinary Manual, “Daily Maintenance Energy Requirements for Dogs and Cats”; Pet Nutrition Alliance, “Calculating Calories Based on Pet Needs”. Checked October 2026. AAHA notes that sedentary and indoor pets may need less than these factors suggest.
| Dog | Default factor | Published range |
|---|---|---|
| Puppy under 4 months | 3.0 | AAHA, Merck 3.0 |
| Puppy 4 months to adult size | 2.0 | AAHA, Merck 2.0 |
| Neutered adult | 1.6 | AAHA 1.4–1.6; Merck 1.6 |
| Intact adult | 1.8 | AAHA 1.6–1.8; Merck 1.8 |
| Inactive or obesity-prone | 1.2 | AAHA 1.0–1.2; Merck 1.4 |
| Weight loss | 1.0 at target weight | AAHA 1.0 |
| Light / moderate / heavy work | 2.0 / 3.0 / 5.0 | AAHA 1.6–2.0 / 2.0–5.0 / 5.0–11.0 |
| Pregnant (last 3 weeks) / nursing | 3.0 / 3.0 | AAHA 3.0 / 3.0 to ≥ 6.0 |
Breed, homemade food and adjusting the amount
By breed: breed matters mainly through weight, so the breed list here only fills in a typical adult weight from the breed standard (see the dog weight chart). Some breeds, such as Labradors, are known to put on weight easily and often do better near the low end of the range.
Homemade diets: the calorie target applies to home-cooked food too, but calories are the easy part — balancing calcium, vitamins and trace minerals is not. Ask your vet to refer you to a board-certified veterinary nutritionist for a complete recipe.
Adjusting: weigh your dog every two to four weeks. If it gains, cut the amount by about 10%; if it loses unintentionally, add 10%. For puppies, track growth with the puppy weight calculator.
Dog Food Calculator FAQ
How accurate is a dog food calculator?
It gives a sensible starting amount. Published factors are averages; the Pet Nutrition Alliance notes individual dogs can vary by as much as 50% from the predicted value. Adjust by weight and body condition over a few weeks.
Why does the result differ from the feeding guide on the bag?
Feeding guides usually assume an active, intact adult and cover a wide weight band. Neutered pet dogs often need less, which is why many dogs fed “by the bag” gain weight.
Where do I find kcal per kg on the label?
Look for “Calorie content” or “Metabolisable energy (ME)”. US labels list kcal/kg and kcal per cup; UK and European labels often give kcal or kJ per 100 g (divide kJ by 4.184 for kcal).
Do treats count?
Yes. AAHA and WSAVA advise keeping treats, chews and table scraps to 10% or less of daily calories. Enter that percentage and the main food amount drops to match.
How much should a puppy eat?
Puppies need about three times their resting energy until four months and about twice after that, split into three or four meals. Puppy needs change fast — recalculate as it grows and follow your vet’s advice.
Is this veterinary advice?
No. It is general information to help you plan. Ask your vet, especially for puppies, pregnant or nursing dogs, overweight dogs and dogs with any illness. For cats, use the cat food calculator.