How many calories does my dog (or cat) need per day?
Enter your pet's weight and life stage to calculate the recommended daily calories (MER), using the standard veterinary formula RER × activity factor.
Recommended daily calories (MER)
630 kcal/day
RER (resting energy): 393.6 kcal/day · factor applied: 1.6×
How the calculation works
The calculation starts with the RER (Resting Energy Requirement), the minimum energy a pet's body burns at rest: RER = 70 × weight(kg)^0.75. This power formula reflects that larger animals burn more total energy, but proportionally less per kilogram, than small animals.
From the RER, we apply a multiplying factor (MER) that varies with the pet's life stage, neuter status, and activity level — a growing puppy may need up to 3 times the RER, while a sedentary neutered adult may need only 1.3 times.
These factors are the same ones used in the nutrition guidelines from AAHA (American Animal Hospital Association) and WSAVA (World Small Animal Veterinary Association), international references in veterinary nutrition.
The result is a starting-point estimate. Your pet's ideal weight and how they respond to the amount of food should be monitored over time — adjust the quantity if they're gaining or losing weight beyond what's expected.
MER factors by life stage and species
| Life stage / activity | Factor (dog) | Factor (cat) |
|---|---|---|
| Puppy/kitten < 4 months | 3× | 2.5× |
| Puppy/kitten 4–12 months | 2× | 2.5× |
| Adult, neutered/spayed | 1.6× | 1.2× |
| Adult, intact (not neutered) | 1.8× | 1.4× |
| Sedentary / prone to obesity | 1.3× | 1× |
| On a weight-loss program | 1× | 0.8× |
| Senior | 1.4× | 1.1× |
| Very active / working dog | 3× | — |
| Pregnant (last third) | 3× | 2× |
| Lactating | 4× | 3× |
Frequently asked questions
What do RER and MER mean?
RER (Resting Energy Requirement) is the energy a pet's body uses just to maintain vital functions at rest. MER (Maintenance Energy Requirement) is the RER multiplied by a factor that accounts for age, neuter status, and activity level — it's the number you should use to set day-to-day food amounts.
Why do neutered dogs need fewer calories?
Neutering lowers the basal metabolic rate in dogs and cats, so the MER factor for neutered animals is lower than for intact animals, even at the same weight and activity level — otherwise the pet tends to gain weight.
Does this work for any breed and age?
The RER/MER formula is the standard used by veterinary nutritionists (AAHA, WSAVA) and works as a starting point for any healthy adult dog or cat. Pets with specific health conditions (kidney disease, diabetes, etc.) may need an individual adjustment from their veterinarian.
What do I do with the calorie result?
Use the result in our daily food portion calculator — it converts the calories into grams based on the caloric density (kcal/kg) listed on the label of the food you use.
Important notice
This calculator is for educational purposes and does not replace a veterinary evaluation. When in doubt, consult a veterinarian.Sources
Related tools
Daily food portion
Convert daily calories into grams of food based on your pet food's caloric density.
Food transition schedule
A 7-day schedule to switch your pet's food without causing digestive issues.
Dog's age in human years
Calculate your dog or cat's real age using the most up-to-date scientific formula.