Cat Age Calculator
Enter your cat’s age to see an approximate human-age comparison and life stage. This is a learning aid, not a measure of health or remaining lifespan.
Your calculator entries stay in this browser page and are not sent to the image provider or analytics.
How the age comparison is calculated
The convention used here places a one-year-old cat at about 15 human years and a two-year-old at about 24. Each year after the second adds four. This follows VCA’s published explanation; it is not a scientific equation for biological age.
For partial years, this calculator linearly interpolates between the year points, including between birth and the first year. That interpolation is our explicit approximation, not an individually validated kitten-development chart. It cannot estimate an unknown cat’s age from appearance.
An age comparison is not a prognosis
A five-year-old cat gives a comparison of 36 human years under this convention. The number does not predict lifespan, disease risk, or when care should change. Different educational charts may use different comparisons.
Life-stage labels follow the AAHA/AAFP ranges: kitten under one year, young adult from one through six, mature adult from seven through ten, and senior after ten. Care decisions still require the cat’s history and veterinary assessment.
Sources and checked date
Checked November 5, 2026. Medical and cost sources have different scopes; follow the method described above rather than treating a number as an individual recommendation.