dogs & cats

Pet calculators

Dog and cat calculators — age in human years, food portions, healthy weight, puppy growth and care costs.
18
calculators
vet
formulas
free
no signup
Page 1 — dogs & cats
Dog age calculator
Your dog's age in human years, adjusted for breed size.
Cat age calculator
Your cat's age in human years, with its life stage.
Dog food calculator
Daily kcal and grams, from the veterinary energy formula.
Cat food calculator
Daily kcal and portions for indoor, outdoor and growing cats.
Dog healthy weight checker
Your dog against its size category's typical healthy range.
Puppy weight estimator
Where your puppy's growth curve is heading.
Pet medication dose calculator
The arithmetic on a dosage your vet has already prescribed.
Pet insurance estimator
A realistic premium range before you gather quotes.
Litter size estimator
How many puppies or kittens to expect, from published averages.
pets — page 2: all pets
9 more calculators →

The formulas vets actually use

Pet calculators are only as good as their formulas. The food calculators here use the standard veterinary resting energy requirement (RER = 70 × kg^0.75) with published life-stage multipliers, and the age converters use the modern staged tables rather than the debunked times-seven rule.

Age conversion, done properly

Dogs and cats mature explosively in their first two years, then age more steadily — and large dogs age faster than small ones later in life. The converters reflect that: a one-year-old dog is a teenager, not a seven-year-old child, and a Great Dane's senior years arrive sooner than a Chihuahua's.

Portions are starting points

Food portion outputs are calculated starting points, not prescriptions: individual metabolism, neutering, activity and body condition move real needs by 20% or more in either direction. Adjust to keep your pet at an ideal body condition score — ribs easily felt, visible waist — and recheck after any change.

When to involve the vet

Every health-adjacent calculator on these pages carries the same message: calculators inform, vets decide. Medication dosing in particular is strictly a veterinary call — our dosage tool only does the arithmetic on a dose your vet has already prescribed.