18 dog years is about 104 human years (AVMA medium dog) or 77 on the UCSD genetic formula.
| Input | Result |
|---|---|
| 18 dog years | AVMA 104 · UCSD 77 |
| +1 year | AVMA 109 · UCSD 78 |
About 104 human years by the AVMA medium-dog guideline, or 77 by the UCSD genetic formula. An 18-year-old dog is about 104 human years (AVMA medium dog) — exceptional longevity; small breeds reach this most often.
The AVMA curve is based on life-stage milestones (puppy, adult, senior); the UCSD formula is fitted to DNA methylation clocks. They agree on the early years and diverge for seniors — both are shown so you can judge.
Yes. Small dogs live longer and age more slowly after year two (about +4 human years per dog year); giant breeds age faster (+6 or more). This calculator uses the medium-dog +5 curve.