Dog food calculator
How many cups of food your dog needs a day, from weight, life stage and the calories on the bag.
- ๐บ๐ธ US federal & state rules
- AAHA nutrition guidelines
- See sources
Food per day
About 2.43 cups
Range 2.27 cups to 2.59 cups. Based on 923 kcal a day. Adjust by watching weight and body shape.
- Calories per day
- 923 kcal (862 kcal to 985 kcal)
- Per meal (2 a day)
- 1.21 cups
- Treats, at most 10%
- 92 kcal
- Resting energy (RER)
- 615 kcal
This is an example. Enter your numbers above and press the button to see your own result.
Other life stages at this weight
| Spayed or neutered adult | 2.43 cups (923 kcal) |
|---|---|
| Intact adult | 2.75 cups (1,046 kcal) |
| Inactive or gains weight easily | 1.78 cups (677 kcal) |
| Puppy under 4 months | 4.86 cups (1,846 kcal) |
| Puppy 4 months to adult | 3.24 cups (1,231 kcal) |
| Active or light work | 2.91 cups (1,108 kcal) |
- A starting point, not veterinary advice. Dogs of the same weight can need 30% more or less, so weigh your dog every few weeks and adjust.
- If you feed treats, subtract their calories from the daily total. Keep treats and extras under 10% of calories.
- Use a standard measuring cup. A scoop or mug often holds more than the cup on the label means.
Show the math
| Weight in kg | 18.14 |
|---|---|
| RER = 70 ร kg^0.75 | 70 ร 18.14^0.75 = 615 kcal |
| Life stage factor (spayed or neutered adult) | 1.4 to 1.6 |
| Calories a day = RER ร factor | 862 kcal to 985 kcal, middle 923 kcal |
| Cups = calories รท kcal per cup | 923 kcal รท 380 = 2.43 cups |
What to do next
How it works
First the calculator finds the resting energy requirement: 70 ร weight in kg^0.75. Then it multiplies by the life stage factor from the 2021 AAHA guidelines, for example 1.4 to 1.6 for a spayed or neutered adult or 3.0 for a puppy under 4 months. When the factor is a range, the middle is used for the main number.
Daily calories divided by the calories per cup on the bag gives cups per day. With kcal per kg, the result is in grams and ounces.
Things to keep in mind
This is not veterinary advice. Pregnant and nursing dogs and working dogs need much more, and those cases are not covered here. Weigh your dog every few weeks and adjust the amount if the weight moves the wrong way.
Sources
Rules applied as of 2026-10-19. See the sources below for details.
- 2021 AAHA Nutrition and Weight Management Guidelines, Box 1Checked 2026-10-19
- WSAVA Nutrition Assessment Guidelines (2011)Checked 2026-10-10
Frequently asked questions
How many cups should I feed my dog?
Work out daily calories, then divide by the kcal per cup on the bag. A 40 lb neutered adult needs about 920 kcal a day, which is about 2.4 cups of a 380 kcal/cup food.
What is RER?
Resting energy requirement, the calories a dog burns at rest: 70 ร body weight in kg to the 0.75 power. A 40 lb (18.1 kg) dog has an RER of about 615 kcal.
How much should I feed for weight loss?
AAHA guidance uses RER at the goal weight (factor 1.0). For a dog going from 40 to 35 lb, that is about 560 kcal a day. Work with your vet on the plan.
Why is the bag's feeding chart different?
Feeding charts cover a wide range of dogs and are often on the generous side. Use this as a starting point, then adjust if your dog gains or loses weight.