Dog Age Calculator
Year 1 ≈ 15, year 2 ≈ +9, then a size-based adder. Click any i for detail.
Dog
Calendar age (years)
i
Age
Decimal years are OK (2.5). |
|
|---|---|
Size band
i
Size
Rough adult-weight band. Small +4 / medium +5 / large +6 / giant +7 human years per calendar year after year 2. |
How to use this calculator
- Enter calendar years.
- Pick a size band.
- Read the human-year sketch.
- Chronological age of a person is the other age page.
Results explained
First year maps to 15, second adds 9 (24 at age 2), then +4/+5/+6/+7 per year by size. The ×7 myth is not used.
Quick reference: dog years
A 5-year-old medium dog is 24 + 5×3 = 39 in this sketch.
| Item | Detail |
|---|---|
| Year 1 | ≈ 15 |
| Year 2 | ≈ 24 |
| After that (medium) | +5 / year |
| Human dates | Chronological age calculator |
Lab vs Chihuahua aging is not a single curve — size is only a coarse lever.
How the estimate is built
age≤1: 15×y; ≤2: 15+9(y−1); else 24 + extra×(y−2).
Example scenario
5-year medium dog → 39 human-year sketch.
FAQ
Why not ×7?
It badly misses puppy years and size differences.
Cat age?
Not this page.
DNA methylation clocks?
Research tools — not this arithmetic.