Cat Age ↔ Human Years Calculator

Convert cat years to human years (and back) with a simple, mobile-friendly calculator. Includes kitten months and an age chart.

Two-way converter Mobile-first Quick chart

Quick answer

Common rule of thumb

A popular guideline is: Year 1 ≈ 15 human years, Year 2 ≈ 24 human years, then +4 human years for each additional cat year.

This is an estimate (cats age differently by breed, lifestyle, and health).

Current conversion
Cat age
Human age
Life stage

Converter

Use months for kittens (e.g., 6 months).

Used for Human → Cat mode.

Cat age to human age chart

Cat age Human age Stage

This chart uses the same rule of thumb as the calculator.

How this calculator works (formulas)

Cat years → human years

  • If cat age < 1 year: we scale the first year up to ~15 human years.
  • At 1 year: ≈ 15 human years
  • At 2 years: ≈ 24 human years
  • After 2 years: +4 human years per cat year

Human years → cat years (reverse)

We reverse the same rule: first map human years into year 1 and 2, then subtract 4 human years per cat year after that.

FAQ

How many human years is 1 cat year?

A common estimate is that a 1-year-old cat is about 15 human years old. This calculator uses that rule of thumb.

How many human years is a 2-year-old cat?

Many charts estimate a 2-year-old cat at about 24 human years, then add ~4 human years for each additional cat year.

How do you convert kitten months to human years?

For kittens under 1 year, this calculator scales up to the “1 year ≈ 15 human years” benchmark. It’s a rough guide — growth is fastest in the first months.