Cat Age Calculator

Year 1 ≈ 15, year 2 ≈ +9, then +4 per year. Click any i for detail.

Jump to result

Cat

Calendar age (years)
i
Age

Decimal years are OK (2.5).

How to use this calculator

  1. Enter the cat's calendar age in years (decimals OK).
  2. Read the human-year sketch.
  3. Compare to the dog-age page if you have both pets.
  4. Remember this ignores breed and indoor/outdoor lifestyle.

Results explained

Year 1 maps to about 15 human years, year 2 adds about 9, then +4 per year after. The ×7 myth is not used.

Quick reference: cat years

A 5-year-old cat is 24 + 3×4 = 36 in this sketch.

ItemDetail
Year 1≈ 15 human years
Year 2≈ 24 human years total
Each year after 2+4 human years
Kitten monthsdecimals OK (0.5 ≈ halfway to year 1 curve)

AAFP-style classroom curve, not a veterinary diagnostic clock.

How the estimate is built

age≤1: 15y; age≤2: 15+9×(age−1); else 24+4×(age−2).

Example scenario

5-year cat → 36 human-year sketch.

FAQ

Why not just multiply by 7?

Cats mature quickly in year one; ×7 misses that early burst.

Do indoor cats live longer?

Lifestyle affects real lifespan; this page does not adjust for it.

Is this the same as dog years?

No. Dogs use a different piecewise curve on the dog-age page.