How much dog food should I feed?
Type your dog’s weight, pick its life stage, and copy the calories per cup from the food bag. The dog food calculator shows the calories your dog needs a day and how many cups to feed, per day and per meal.
- Calories a day
- 629
A 22 lb dog needs about 629 kcal a day: 1.8 cups of this food, 0.9 cups per meal.
- Cups a daycups
- 1.8
- Cups per mealcups
- 0.9
- Resting energy (RER)kcal
- 393
- Factor used
- 1.6
Calories a day: 629. A 22 lb dog needs about 629 kcal a day: 1.8 cups of this food, 0.9 cups per meal.
How to calculate
Estimates how many calories a dog needs a day (RER = 70 × kg^0.75 times a life-stage factor) and how many cups or grams of its food that is, per day and per meal.
Example with the default inputs (Dog’s weight 22 lb, Life stage Adult, neutered (1.6), Calories per cup 350, Meals a day 2): A 22 lb dog needs about 629 kcal a day: 1.8 cups of this food, 0.9 cups per meal.
Method: RER = 70 × (weight in kg)^0.75 kcal a day; calories a day = factor × RER; cups = calories ÷ kcal per cup; grams = calories ÷ kcal per kg × 1,000.
- The factors are starting points for healthy dogs; a vet adjusts them to the dog’s body condition.
- Treats and table food are not counted: take their calories off the daily total.
- A cup is a standard 8 oz measuring cup, the one the label’s kcal per cup refers to.
Worked examples
Each example is checked against the calculator on every build.
- Dog’s weight 67.13 lb, Life stage Weight loss (1.0), Calories per cup 350, Meals a day 2 gives Resting energy (RER) 907.378559, Calories a day 907.378559, Cups a day 2.59251, Cups per meal 1.296255.Source: Today’s Veterinary Nurse, Nutrition Math 101 (Carlson, 2023): a 30.45 kg dog has RER = 70 × 30.45^0.75 = 907 kcal a day; weight loss uses 1.0 × RER, https://todaysveterinarynurse.com/nutrition/veterinary-nutrition-math/
- Dog’s weight 22.05 lb, Life stage Adult, neutered (1.6), Calories per cup 350, Calories per kg (optional) 3,600, Meals a day 2 gives Resting energy (RER) 393.638928, Calories a day 629.822284, Cups a day 1.799492, Grams a day 174.950635.Source: Ohio State University Veterinary Medical Center, Companion Animal Nutrition Support Service: RER = 70 × kg^(3/4), about 400 Calories a day for a 10 kg dog, https://vmc.vet.osu.edu/services/companion-animal-nutrition-support-service; dogs: intact 1.8, neutered 1.6, obesity prone 1.4, puppies under 4 months 3, over 4 months 2 × RER, https://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals
- Dog’s weight 50 lb, Life stage Adult, intact (1.8), Calories per cup 400, Meals a day 2 gives Resting energy (RER) 727.48635, Calories a day 1,309.475429, Cups a day 3.273689.Source: Dogs: intact 1.8, neutered 1.6, obesity prone 1.4, puppies under 4 months 3, 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), Calories per cup 420, Meals a day 4 gives Calories a day 702.17732, Cups per meal 0.417963, Factor used 3.Source: Dogs: intact 1.8, neutered 1.6, obesity prone 1.4, puppies under 4 months 3, over 4 months 2 × RER, https://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals
- Dog’s weight 44.09 lb, Life stage My vet’s factor, Factor × RER 4, Calories per cup 500, Meals a day 2 gives Calories a day 2,648.076505, Factor used 4.Source: Dogs: intact 1.8, neutered 1.6, obesity prone 1.4, puppies under 4 months 3, over 4 months 2 × RER, https://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals (factor set by the vet)
How it works
The weight is turned into kilograms first (1 lb = 0.45359237 kg). Then:
- Resting energy (RER) = 70 × (weight in kg)^0.75 kcal a day.
- Calories a day = factor × RER, with the factor from the life stage:
| Life stage | Factor |
|---|---|
| Adult, neutered | 1.6 |
| Adult, intact | 1.8 |
| Adult, prone to weight gain | 1.4 |
| Weight loss | 1.0 |
| Puppy under 4 months | 3.0 |
| Puppy 4 months to adult | 2.0 |
| My vet's factor | the number typed (0.5 to 8) |
- Cups a day = calories a day ÷ calories per cup.
- Cups per meal = cups a day ÷ meals a day.
- Grams a day = calories a day ÷ calories per kg × 1,000, shown only when calories per kg are typed.
Calories and grams show as whole numbers, cups to 2 decimal places. The maths runs in floating point and rounds for display only.
Assumptions: the factors are starting points for a healthy dog; a vet adjusts them to the dog's body condition, activity and health. For weight loss, type the target weight. Treats and table food are not counted: take their calories off the daily total. A cup is the standard 8 fl oz measuring cup that the label's kcal per cup refers to.
Rules
- Weight from 0.5 kg to 120 kg (about 1.1 lb to 264.6 lb); calories per cup from 50 to 1,500; calories per kg from 300 to 9,000 (optional); meals a day from 1 to 6 (whole). A value outside that shows a message on its field.
Worked examples by hand
A 30.45 kg dog losing weight (Today's Veterinary Nurse). RER = 70 × 30.45^0.75 = 907.38 kcal; factor 1.0, so 907 kcal a day. At 350 kcal a cup: 2.59 cups a day, 1.30 cups per meal.
A 10 kg neutered adult (Ohio State: about 400 Calories at rest). RER = 70 × 10^0.75 = 393.64 kcal; × 1.6 = 629.82 kcal a day. At 350 kcal a cup: 1.80 cups. At 3,600 kcal per kg: 629.82 ÷ 3,600 × 1,000 = 175 g.
A 50 lb intact adult. 50 lb = 22.68 kg. RER = 70 × 22.68^0.75 = 727.49 kcal; × 1.8 = 1,309.48 kcal. At 400 kcal a cup: 3.27 cups.
A 5 kg puppy under 4 months. RER = 70 × 5^0.75 = 234.06 kcal; × 3 = 702.18 kcal. At 420 kcal a cup: 1.67 cups a day, 0.42 cups in each of 4 meals.
A 20 kg working dog, vet's factor 4. RER = 70 × 20^0.75 = 662.02 kcal; × 4 = 2,648.08 kcal a day.
Other questions people ask
How much should I feed my dog a day?
Work out its calories a day, then divide by the calories in a cup of its food. A 10 kg (22 lb) neutered adult needs about 70 × 10^0.75 × 1.6 = 630 kcal a day; with food at 350 kcal a cup that is 1.8 cups a day.
What is RER?
The resting energy requirement: the calories a dog burns at rest. RER = 70 × (body weight in kg)^0.75. A 30.45 kg dog has an RER of about 907 kcal a day.
What life-stage factor should I use?
The Merck Veterinary Manual gives 1.6 × RER for a neutered adult, 1.8 for an intact adult, 1.4 for an adult prone to gaining weight, 3 for a puppy under 4 months and 2 for a puppy from 4 months to adult. For weight loss, 1.0 × RER at the target weight is a common start. Working dogs need more; ask your vet.
Where do I find the calories per cup?
On the food label. Most dog food labels give the calories as kcal per kilogram and kcal per cup or can. Type the kcal per kilogram as well to get grams, which is more exact than cups.
Why does a big dog not need twice the food of a dog half its size?
Energy needs grow with weight to the power 0.75, not in step with weight. A 20 kg dog needs about 70 × 20^0.75 = 662 kcal at rest, only 1.68 times the 394 kcal of a 10 kg dog.
Is this amount exact for my dog?
No. The Merck Veterinary Manual calls any such amount a starting point: dogs of the same weight can need more or less. Weigh your dog every few weeks and feed a little more or less to keep a healthy body condition; your vet can help.