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Cat Age Calculator

Convert a cat's age to human years with the veterinary age chart, and see its life stage.

In human years

About 56

Life stage
Mature adult (7–10 years)

An age comparison, not a health check — cats age differently by breed, weight and indoor or outdoor life. Over 25 years extends the +4 rule beyond the chart.

Cat age chart (AAFP–AAHA)

CatHuman
6 months10
1 year15
2 years24
4 years32
6 years40
8 years48
10 years56
12 years64
15 years76
18 years88
20 years96
25 years116

Show the work

  1. Age in months

    months = years × 12 + months

    10 × 12 + 0 = 120 months

  2. 2 years = 24, then 4 more for each year after

    human = 24 + (months − 24) ÷ 12 × 4

    24 + (120 − 24) ÷ 12 × 4 = About 56

How it works

AAFP–AAHA chart (2010): 1 year = 15 human years, 2 years = 24, then +4 for every year after (e.g. 10 = 56); months under 2 years follow the chart; life stages from the 2021 AAHA/AAFP Feline Life Stage Guidelines

Questions

How does the cat age calculator work?
AAFP–AAHA chart (2010): 1 year = 15 human years, 2 years = 24, then +4 for every year after (e.g. 10 = 56); months under 2 years follow the chart; life stages from the 2021 AAHA/AAFP Feline Life Stage Guidelines.
What do I need to enter?
Years, Months. Optional fields can be left blank.

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