How the dog food calculator works
Every dog has a baseline calorie need called the resting energy requirement (RER), the energy used at rest. Veterinarians calculate it with the formula RER = 70 × (body weight in kg)0.75. That baseline is then multiplied by a factor for life stage and activity to give the maintenance energy requirement (MER), which is how many calories your dog needs per day.
Finally, the calculator divides daily calories by the calories in one cup of your food. That is why the kcal per cup number matters so much. Dog foods range from under 300 to over 500 kcal per cup, so "2 cups a day" can mean very different amounts of food.
Life stage multipliers used
| Life stage | Multiplier (× RER) |
|---|---|
| Adult, spayed/neutered | × 1.6 |
| Adult, intact | × 1.8 |
| Inactive / prone to weight gain | × 1.2 |
| Senior, less active | × 1.4 |
| Weight loss (use ideal weight) | × 1 |
| Active / light work | × 2 |
| Heavy work / working dog | × 3 |
| Puppy under 4 months | × 3 |
| Puppy 4 months to adult | × 2 |
Dog feeding chart by weight
This chart shows estimated daily calories for a typical spayed or neutered adult dog (RER × 1.6) and an inactive dog (RER × 1.2), plus cups per day for a food with 350 kcal per cup. If your food has a different calorie density, use the calculator above.
| Dog weight | Calories/day (typical adult) | Cups/day at 350 kcal | Calories/day (inactive) |
|---|---|---|---|
| 5 lb (2.3 kg) | 207 kcal | 0.59 cups | 155 kcal |
| 10 lb (4.5 kg) | 348 kcal | 0.99 cups | 261 kcal |
| 15 lb (6.8 kg) | 472 kcal | 1.35 cups | 354 kcal |
| 20 lb (9.1 kg) | 585 kcal | 1.67 cups | 439 kcal |
| 30 lb (13.6 kg) | 794 kcal | 2.27 cups | 595 kcal |
| 40 lb (18.1 kg) | 985 kcal | 2.81 cups | 738 kcal |
| 50 lb (22.7 kg) | 1,164 kcal | 3.33 cups | 873 kcal |
| 60 lb (27.2 kg) | 1,335 kcal | 3.81 cups | 1,001 kcal |
| 70 lb (31.8 kg) | 1,498 kcal | 4.28 cups | 1,124 kcal |
| 80 lb (36.3 kg) | 1,656 kcal | 4.73 cups | 1,242 kcal |
| 90 lb (40.8 kg) | 1,809 kcal | 5.17 cups | 1,357 kcal |
| 100 lb (45.4 kg) | 1,958 kcal | 5.59 cups | 1,468 kcal |
| 120 lb (54.4 kg) | 2,244 kcal | 6.41 cups | 1,683 kcal |
Why the bag's feeding guide is often too much
Feeding guides on dog food bags are usually written for young, active, intact dogs, and they give a wide range. Most pet dogs are spayed or neutered and less active, so following the top of the bag range is a common reason dogs gain weight. Use the calculated amount as a starting point, then adjust based on your dog's body condition.
How to check you are feeding the right amount
- Weigh your dog every 2-4 weeks. If weight is creeping up, reduce food by about 10%; if your dog is losing weight unintentionally, increase by 10%.
- Check body condition. You should be able to feel the ribs easily under a thin layer of fat and see a waist from above.
- Measure with a scale, not a scoop. Weighing food in grams is more accurate than cups. Check the grams per cup on your bag.
- Count treats. Treats should be under 10% of daily calories. Reduce meals by the calories you give as treats.
Feeding puppies
Puppies need roughly two to three times the resting energy of an adult. Choose "Puppy under 4 months" (× 3.0) or "Puppy 4 months to adult" (× 2.0), use their current weight, and recalculate every couple of weeks as they grow. Large-breed puppies should eat a large-breed puppy formula to support controlled growth. To estimate adult size, try our puppy weight calculator.
Feeding for weight loss
For weight loss, veterinarians typically feed RER calculated at the dog's ideal weight (× 1.0), not current weight, aiming to lose 1-2% of body weight per week. Our dog calorie calculator does this for you and estimates how long it will take. Always plan weight loss with your vet.
Frequently asked questions
How many cups of food should I feed my dog a day?
It depends on weight, activity and the calories per cup of your food. As an example, a 40 lb neutered adult needs about 985 kcal per day, which is about 2.8 cups of a 350 kcal/cup food. Use the calculator for your dog.
How many times a day should I feed my dog?
Most adult dogs do well on two meals a day. Puppies under 6 months usually eat 3-4 meals a day.
Where do I find calories per cup?
Pet food labels in the US must list calorie content, usually as kcal/kg and kcal/cup, near the guaranteed analysis. If it is missing, check the manufacturer website.
Is it better to feed wet or dry food?
Both can be complete and balanced. Wet food has more water and fewer calories per gram; dry food is more calorie dense. Use the kcal values for whatever you feed.
Should I feed based on current or ideal weight?
For a dog at a healthy weight, use current weight. For an overweight dog, vets calculate calories based on ideal weight.