Pet calorie calculator
Enter your dog or cat’s weight and life stage for an estimate of how many calories (kcal/day) they need to stay at a healthy weight. Worked out using the standard veterinary RER/MER formula (WSAVA).
A guide, not a diagnosis
This is a guide based on the standard veterinary formula, not a substitute for advice from your vet. Individual needs vary with metabolism, health and activity.
How the numbers are worked out
We use the standard veterinary RER/MER formula (WSAVA). First we calculate your pet’s Resting Energy Requirement — the energy they’d burn at rest — then adjust it for life stage and activity to give the Maintenance Energy Requirement (their estimated daily need).
- RER = 70 × (body weight in kg)0.75
- MER = RER × a life-stage / activity factor
Results are rounded to the nearest 5 kcal. Treats count too — they should make up no more than around 10% of daily calories. Always cross-check against the feeding guide on your food’s packaging.