How to use this dog food calculator
Enter your dog's weight and choose its life stage and activity level. Then copy two numbers from your dog food bag: the calories per kilogram (kcal/kg) and, if it's listed, the calories per cup. In the US, both appear in the "calorie content" statement near the guaranteed analysis. The calculator gives the daily amount in cups and grams, splits it into meals, and shows how long a bag lasts and what feeding costs per month.
How the daily calories are calculated
Veterinary nutritionists start with the resting energy requirement (RER), the calories a dog burns at rest in a comfortable environment:
RER = 70 × (body weight in kg)0.75
Then they multiply the RER by a factor for life stage and activity to get the maintenance energy requirement (MER), the calories your dog needs a day. The factors below are the standard ones used in the WSAVA Global Nutrition Guidelines and the Merck Veterinary Manual:
| Dog | Daily calories |
|---|---|
| Puppy under 4 months | 3.0 × RER |
| Puppy 4 months to adult size | 2.0 × RER |
| Adult, spayed or neutered | 1.6 × RER |
| Adult, intact | 1.8 × RER |
| Inactive adult or senior, prone to weight gain | 1.2–1.4 × RER |
| Weight loss | 1.0 × RER at ideal weight |
| Active or working dog | 2.0–5.0 × RER |
Worked example: a 30 lb (13.6 kg) neutered adult dog. 13.60.75 = 7.09, so RER = 70 × 7.09 = 496 kcal. With a factor of 1.6, the dog needs about 794 kcal a day. If the food has 380 kcal per cup, that's 794 ÷ 380 = 2.1 cups a day, or about 1 cup per meal. At 3,600 kcal/kg, it's 794 ÷ 3,600 × 1,000 = about 220 g.
Calories a day by weight
Typical daily calories for spayed or neutered adult dogs (1.6 × RER):
| Dog's weight | Daily calories | Cups at 380 kcal/cup |
|---|---|---|
| 10 lb (4.5 kg) | ≈ 350 kcal | ≈ 0.9 |
| 20 lb (9 kg) | ≈ 585 kcal | ≈ 1.5 |
| 30 lb (13.6 kg) | ≈ 795 kcal | ≈ 2.1 |
| 50 lb (22.7 kg) | ≈ 1,165 kcal | ≈ 3.1 |
| 70 lb (31.8 kg) | ≈ 1,500 kcal | ≈ 3.9 |
| 90 lb (40.8 kg) | ≈ 1,810 kcal | ≈ 4.8 |
Why the result may differ from the bag
Feeding guides on dog food bags are written for an average, fairly active, intact dog, so they often overestimate what a neutered pet dog needs. Dogs also vary: two dogs of the same weight can need 20–30% different amounts. Treat the result as a starting point. Weigh your dog every two to four weeks, and adjust the amount by about 10% if your dog is gaining or losing weight it shouldn't.
Is my dog at a healthy weight?
Vets use a 9-point body condition score. At an ideal score of 4 or 5, you can feel the ribs easily under a thin layer of fat without pressing, you can see a waist when you look down from above, and the belly tucks up when you look from the side. If you can't feel the ribs, your dog is probably overweight. Use its ideal weight in the calculator and choose the weight-loss setting, and ask your vet for a plan.
Treats count too
The usual rule is that treats, chews and table scraps should make up no more than 10% of daily calories. If your dog gets a lot of treats, reduce its meals so the total stays the same. Use a kitchen scale or a proper measuring cup: a "cup" scooped with a mug can easily be 25% too much.
Frequently asked questions
How much should I feed my dog a day?
It depends on weight, age, activity and the calories in your food. A typical neutered 30 lb dog needs about 800 kcal a day, which is about 2 cups of a 380 kcal/cup dry food. Enter your dog's details above for a personal estimate.
How many cups of food should a 50 lb dog eat?
A neutered, moderately active 50 lb dog needs about 1,165 kcal a day. With a typical dry food of 350–400 kcal per cup, that's about 3 to 3⅓ cups a day, split into two meals.
Should I feed my dog once or twice a day?
Most vets recommend at least two meals a day for adult dogs, and three or four for young puppies. Splitting food helps with hunger and digestion and, for large deep-chested breeds, may lower the risk of bloat.
How much should I feed a puppy?
Puppies need about 3 times their resting energy until 4 months, then about 2 times until they reach adult size. Use your puppy's current weight and recalculate every couple of weeks as it grows. Feed a food labeled for growth.
Where do I find the calories in my dog food?
In the US, the bag must show a calorie content statement such as "3,650 kcal/kg, 380 kcal/cup", usually near the guaranteed analysis. Elsewhere, look for the metabolizable energy (ME), often given per 100 g; multiply by 10 to get kcal/kg.
Calorie needs vary between dogs. This is a starting estimate, not a diet plan. Ask your vet before changing your dog's food, and for puppies, pregnant or nursing dogs, and dogs with medical conditions.