Pet calorie calculator
Answer nine short questions — weight, life stage, body condition and how many treats a day — for an estimated range of how many calories (kcal/day) your dog or cat needs to hold a healthy weight. Worked out using the standard veterinary RER/MER formula (WSAVA), and the answer is on the page before anything is asked for in return.
The energy formula uses a different set of multipliers for each — a neutered cat sits well below a neutered dog.
Only so the answer reads as being about your pet rather than a generic one. It stays in this browser unless you choose to save the profile at the end.
It doesn’t change the calorie formula — it gives us a published healthy adult weight range, which is how we can estimate a weight if you haven’t got one.
This is the multiplier applied to resting energy. A growing puppy can need two to three times what a neutered adult of the same weight needs.
Weight on its own can’t tell us whether to feed for maintenance or for loss. Look from above and feel along the ribs — the shape you pick moves the weight the sum is run on.
Just right: Ribs are easy to feel under a thin layer, with a waist behind them and a tucked-up belly from the side.
Everything is calculated per kilo of body weight — this is the single number the answer rests on.
Treats should stay under about 10% of the day’s calories. We take your share off the meal rather than adding it on top, which is what that guideline actually means.
We ask for the share rather than a count on purpose: a dental stick can be 100 kcal and a training pellet 2, so a number of treats only becomes calories by guessing at a figure per treat.
It changes which foods we could suggest. It does not change the calorie figure, and nothing here is medical advice — an allergy worth managing is worth a vet’s input.
So a portion can be worked out for the food you already buy, rather than talking you into a switch you didn’t ask for.
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
Body condition changes the weight, not the formula. The widely used rule of thumb is that each point away from ideal on the nine-point veterinary body-condition scale is about 10% of body weight. The five-point scale here is the same scale at half the resolution, so each step is about 20% — and the sum is run on the healthy weight your pet is heading for, which is the standard clinical approach, rather than on the weight they are carrying today.
Treats come out of the total, not on top of it. The usual guidance is that treats should stay under about 10% of daily calories, so the share you pick is taken off the meal budget. We ask for a share rather than a count because a dental stick can be 100 kcal and a training pellet 2 — turning a count into calories would mean inventing a figure per treat.
Figures are rounded to the nearest 5 kcal and shown as a range: published life-stage factors are representative values, not measurements of your animal, so we show ±10% around the result. That band is our own way of showing the uncertainty — it is not itself a published figure. Nobody clinical has reviewed this page, so nobody clinical is named on it. Always cross-check against the feeding guide on your food’s packaging, and ask your vet.
Sources
The RER/MER calorie formula follows WSAVA global nutrition guidance. It’s a starting estimate — individual needs vary with metabolism, neutering, health and activity. Always cross-check your food’s feeding guide and ask your vet.