How many dog calories per day?
Type your dog’s weight and pick its life stage. The dog calorie calculator finds the resting energy requirement, multiplies it by the Merck Veterinary Manual factor, and can turn the calories into cups or cans of food.
- Calories per day
- 794
A 30 lb dog needs about 794 calories a day at 1.6 × RER.
- Resting energy (RER)kcal/day
- 496
- Life-stage factor
- 1.6
- RER by the linear formulakcal/day
- 478
Calories per day: 794. A 30 lb dog needs about 794 calories a day at 1.6 × RER.
Calories per day by dog’s weight
How to calculate
Estimates a dog’s daily calories from its weight and life stage: the resting energy requirement 70 × kg^0.75 times the Merck Veterinary Manual factor, with cups or cans of food.
Example with the default inputs (Dog’s weight 30 lb, Life stage Neutered adult (× 1.6)): A 30 lb dog needs about 794 calories a day at 1.6 × RER.
Method: RER = 70 × (body weight in kg)^0.75 kcal a day; calories per day = RER × the life-stage factor (neutered adult 1.6, intact adult 1.8, inactive or obesity prone 1.4, puppy under 4 months 3.0, puppy 4 months to adult 2.0); cups or cans = calories ÷ the food’s calories per cup or can.
- The factors are the Merck Veterinary Manual’s for healthy dogs. Dogs of the same weight can need 30% more or less, so the result is a starting point: weigh your dog every few weeks and adjust.
- Working, pregnant, nursing, sick and overweight dogs need a vet’s plan; this page has no factor for them.
- This page is for information only and is not veterinary advice.
Worked examples
Each example is checked against the calculator on every build.
- Dog’s weight 22.05 lb, Life stage Neutered adult (× 1.6) gives Resting energy (RER) 393.638928, Calories per day 629.822284, RER by the linear formula 370.Source: Merck Veterinary Manual, Nutritional Requirements of Small Animals (S. L. Sanderson, reviewed Nov 2023): RER = 70 × BW(kg)^0.75 or 30 × BW(kg) + 70 for > 2 kg and < 45 kg; puppies under 4 months 3 × RER, over 4 months 2 × RER, https://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals
- Dog’s weight 30 lb, Life stage Intact adult (× 1.8), Food calories per cup or can 350 gives Resting energy (RER) 495.950448, Calories per day 892.710806, Cups or cans per day 2.550602.Source: Merck Veterinary Manual, Nutritional Requirements of Small Animals (S. L. Sanderson, reviewed Nov 2023): RER = 70 × BW(kg)^0.75 or 30 × BW(kg) + 70 for > 2 kg and < 45 kg; puppies under 4 months 3 × RER, over 4 months 2 × RER, https://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals
- Dog’s weight 11.02 lb, Life stage Puppy under 4 months (× 3.0) gives Resting energy (RER) 234.059107, Calories per day 702.17732, Life-stage factor 3.Source: Merck Veterinary Manual, Nutritional Requirements of Small Animals (S. L. Sanderson, reviewed Nov 2023): RER = 70 × BW(kg)^0.75 or 30 × BW(kg) + 70 for > 2 kg and < 45 kg; puppies under 4 months 3 × RER, over 4 months 2 × RER, https://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals
- Dog’s weight 110.2 lb, Life stage Inactive or obesity prone (× 1.4) gives Resting energy (RER) 1,316.211083, Calories per day 1,842.695516.Source: Merck Veterinary Manual, Nutritional Requirements of Small Animals (S. L. Sanderson, reviewed Nov 2023): RER = 70 × BW(kg)^0.75 or 30 × BW(kg) + 70 for > 2 kg and < 45 kg; puppies under 4 months 3 × RER, over 4 months 2 × RER, https://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals
How it works
- Body weight in kg: a weight typed in pounds, ounces or grams is changed to kilograms (1 lb = 0.45359237 kg, 1 oz = 0.028349523125 kg).
- RER = 70 × (weight in kg)^0.75 kilocalories a day, in double-precision floating point.
- Calories per day = RER × the life-stage factor:
| Life stage | Factor |
|---|---|
| Neutered adult | 1.6 |
| Intact adult | 1.8 |
| Inactive or obesity prone | 1.4 |
| Puppy under 4 months | 3.0 |
| Puppy 4 months to adult | 2.0 |
- Cups or cans per day (when you type the food’s calories) = calories per day ÷ kcal per cup or can.
- RER by the linear formula = 30 × kg + 70, shown only when the weight is more than 2 kg and less than 45 kg (Merck’s range for it). It is for comparison; the daily calories always use 70 × kg^0.75.
Rules
- Weight from 0.5 kg to 100 kg, both included, checked in kilograms. In pounds that is 1.1023113… lb to 220.4622621… lb, so 1.11 lb is the smallest and 220.46 lb the largest two-decimal pound value accepted. Food calories from 1 to 3,000 kcal per cup or can; leave it empty to skip the portions.
- Merck’s puppy rows are “under 4 months” and “over 4 months”; the page puts a puppy of exactly 4 months in the second row.
- The result is a starting point for a healthy dog, not a prescription.
Output format. Calories show as whole kcal a day, the factor with 1 decimal, and cups or cans with 2 decimals, each rounded half up.
Worked examples by hand
A 10 kg neutered adult. 10^0.75 = 5.62341. RER = 70 × 5.62341 = 393.64 kcal; × 1.6 = 629.82 kcal a day. Linear RER: 30 × 10 + 70 = 370 kcal.
A 30 lb intact adult on 350 kcal-per-cup food. 30 lb = 13.6077711 kg; 13.6077711^0.75 = 7.08501. RER = 495.95 kcal; × 1.8 = 892.71 kcal a day; ÷ 350 = 2.55 cups a day.
A 5 kg puppy under 4 months. RER = 70 × 5^0.75 = 70 × 3.34370 = 234.06 kcal; × 3 = 702.18 kcal a day.
A 50 kg obesity-prone dog. RER = 70 × 50^0.75 = 70 × 18.80302 = 1,316.21 kcal; × 1.4 = 1,842.70 kcal a day. 50 kg is over 45 kg, so the linear formula is not shown.
Other questions people ask
How many calories does a dog need a day?
A 30 lb (13.6 kg) neutered adult needs about 70 × 13.6^0.75 × 1.6 = 794 kcal a day; the same dog intact needs about 893 kcal. A 10 kg neutered dog needs about 630 kcal.
What is RER?
The resting energy requirement: the calories a dog burns at rest in a comfortable room. RER = 70 × body weight in kg raised to the power 0.75. A 10 kg dog’s RER is about 394 kcal.
Which factor fits my dog?
The Merck Veterinary Manual gives 1.6 × RER for a neutered adult, 1.8 for an intact adult and 1.4 for an obesity-prone dog. Puppies need 3 × RER until 4 months old and 2 × RER from then until they are grown.
How much food is that?
Find the kcal per cup or per can on the food label and type it. A 30 lb intact dog at 893 kcal a day, on food with 350 kcal per cup, needs about 2.55 cups a day, split into meals. Count treats too.
Why are there two RER numbers?
Merck gives two formulas. 70 × kg^0.75 works for any weight; the linear 30 × kg + 70 is a shortcut for dogs over 2 kg and under 45 kg. The page uses the first and shows the second for comparison.
How do I feed a dog that needs to lose weight?
Ask your vet for a target weight and a plan, and weigh the dog often. Dogs of the same weight can need 30% more or fewer calories, so any formula is only a starting point.