Most people know the old "multiply by 7" rule — but the real math is more surprising. Dogs age rapidly as puppies, then slow down. And size matters too: small dogs outlive large ones by years.
Enter your age (or your dog's age) and see the conversion. This uses the traditional 7× formula — a fun approximation! For the more accurate breakdown by breed size, see the table below.
Using the traditional 7× approximation. Actual aging varies by size and breed.
Using the traditional 7× approximation. See the table below for size-adjusted estimates.
Dogs age quickly when young and slow down later — and larger breeds age faster than smaller ones. Use this chart for more accurate estimates:
| Dog's Age | Small Dog Under 20 lbs |
Medium Dog 21–50 lbs |
Large Dog Over 50 lbs |
|---|---|---|---|
| 1 | 15 | 15 | 15 |
| 2 | 24 | 24 | 24 |
| 3 | 28 | 28 | 28 |
| 5 | 36 | 36 | 36 |
| 7 | 44 | 47 | 50 |
| 10 | 56 | 60 | 66 |
| 12 | 64 | 69 | 77 |
| 15 | 76 | 83 | 93 |
A 1-year-old dog is roughly equivalent to a 15-year-old human — not 7, as the old rule suggests.
Small dogs can live 15–18 years while large breeds often live just 8–10. Smaller bodies age more slowly after adulthood.
A 2019 study used DNA methylation patterns to map dog aging — and found the real curve is logarithmic, not linear.
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