Dog Food Calculator

Daily calories and cups from weight, life stage, and food energy.

Biology and LifeUpdated 2026-10-112 min read
Dog Food Calculator
Printed on the bag.
Daily calories
...
Cups per day...
Resting need...

What it does

Bag charts feed averages while vet math feeds the dog in front of you. Resting need scales with metabolic weight, 70 times kilos to the 0.75, then a life stage factor sets the day: 1.6 for the typical neutered adult. The tool above turns that into calories and cups from the bag label.

The default is a 20 kg neutered adult on 350 kcal per cup food. Resting need is 662 kcal, the day needs 1,059 kcal, and the bowl gets 3 cups. Imperial mode weighs 44.1 lb and lands on the same three figures through conversion.

Published factors back every option. Veterinary nutrition tables set neutered adults at 1.6, intact at 1.8, quiet or senior dogs near 1.2 to 1.4, weight loss at 1.0 of target weight, and growing puppies at 2.5. Resting need itself is the same 70 times metabolic weight everywhere.

Charts start the conversation that ribs finish. Aim for a lean 4 to 5 of 9 body condition with ribs felt and waist visible, then feed the trend: gaining means less, ribby means more. Puppies, workers, pregnancy, and illness all break the standard factors, so confirm those with a vet.

How to use

  1. Pick metric (kg) or imperial (lb).
  2. Weigh the dog at its ideal weight.
  3. Pick the closest life stage.
  4. Type the food energy from the bag in kcal per cup.
  5. Read daily calories first, cups beside them.

Formula

RER = 70 x kg^0.75. Daily = RER x stage factor. Cups = daily / kcal per cup.
RER
Resting energy requirement in kcal per day.
factor
1.0 loss, 1.3 senior, 1.6 neutered, 1.8 intact, 2.5 puppy.
kcal/cup
Metabolizable energy printed on the food label.

Use ideal weight, not current weight, for chunky or thin dogs. Treats come out of the daily total, capped near 10%.

Worked example

Example: 20 kg neutered adult

Metric defaults: 20 kg, neutered, 350 kcal/cup.

  1. Metabolic weight: 20^0.75 = 9.457.
  2. RER: 70 x 9.457 = 662 kcal.
  3. Daily: 662 x 1.6 = 1,059 kcal.
  4. Cups: 1,059 / 350 = 3 cups.
  5. Tool shows 1,059 kcal, 3 cups, 662 kcal RER.

Reference table

Neutered adults at 350 kcal/cup
WeightDailyCups
5 kg375 kcal1.1 cups
10 kg630 kcal1.8 cups
20 kg1,059 kcal3 cups
30 kg1,436 kcal4.1 cups

Limits

  • Starting estimates, not prescriptions.
  • Ideal weight assumed; adjust for condition.
  • Needs swing 50% around the figure.
  • Vet decides illness, pregnancy, and work rations.

Common mistakes

  • Feeding current weight on an obese dog.
  • Adding treats on top of the daily total.
  • Guessing kcal per cup instead of reading the bag.
  • Switching foods without remeasuring cups.
  • Free feeding a weight loss case.

Try it yourself

Quick checks. Answers sit tucked under each question.

10 kg puppy at 350 kcal/cup?

RER 394 kcal, daily 394 x 2.5 = 984 kcal, 2.8 cups.

30 kg intact adult at 320 kcal/cup?

RER 897 kcal, daily 897 x 1.8 = 1,615 kcal, 5 cups.

44.1 lb neutered adult?

44.1 lb is 20 kg, so 1,059 kcal and 3 cups.

Questions

How much for a 20 kg adult?

1,059 kcal a day, about 3 cups at 350 kcal/cup.

What is RER?

Rest calories: 70 times kilos to the 0.75.

Neutered versus intact?

Factors 1.6 versus 1.8 of the same resting need.

How are cups found?

Daily calories divided by the bag kcal per cup.

Where do treats fit?

Inside the daily total, capped near 10%.

Puppy or adult factor?

Puppies run 2.5; adults 1.6 neutered or 1.8 intact.

Sources

How this page was checked. The formula above was matched against the cited sources, and the worked example was run through the tool on this page before publishing. If you spot an error, contact us so we can fix it and note the correction.