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FPSPOT

Dog & Cat Age Calculator

Estimate a rough human-equivalent age from completed pet years. This guide does not calculate a birth-date age or assess health, and the dog rule does not adjust for breed or body size.

Estimate human-equivalent age

The dog guide is for medium-sized dogs; do not treat it as a breed-specific conversion.

A whole number from 1 to 18. Partial first years and older ages are outside this version’s supported range.

Enter 1–18 completed years. Cat guide: first year 15, second year 24, then add 4 each year. Medium-sized dog guide: first year 15, second year 24, then add about 5 each year. These are rough guides, not breed-specific biological ages.

Enter the values, then calculate.

American Kennel Club: dog-year guide

Source for the approximate medium-sized dog rule.

Purina UK: cat-age chart

Source chart gives 1 year = 15, 2 years = 24, and 6 years = 40.

Examples and limits

A 2-year-old cat is about 24 human-equivalent years; a 6-year-old cat about 40. The approximate medium-sized dog guide gives about 44 at 6 years. Breed, size and individual health affect real aging.

Why completed years?

The cited rules are yearly guides. This version supports 1–18 completed years and does not invent monthly interpolation, puppy/kitten conversion or a breed-specific model. Consult a veterinarian for health and care decisions.