Dog Age Calculator
Fill in the values and the answer updates as you type.
How the Dog Age Calculator works
A dog's first year counts as about 15 human years, the second as 9 more (24 total), and each later year adds 4 for small, 5 for medium, or 6 for large dogs. Larger breeds age faster. This is an estimate; your vet can judge your dog's real condition.
Inputs and results
The Dog Age Calculator takes 2 inputs and gives 3 results.
What you enter
- Dog age (years) — starts at 5.
- Dog size — starts at Medium (9 to 23 kg). Choose from: Small (under 9 kg), Medium (9 to 23 kg) and Large (over 23 kg).
What you get
- Human age equivalent
- Life stage
- Dog years per real year after age 2
Example: Dog Age Calculator with the starting values
With dog age 5 years and dog size Medium (9 to 23 kg), the calculator returns:
| Human age equivalent | 39 |
|---|---|
| Life stage | Adult |
| Dog years per real year after age 2 | 5 |
Change any value above and the results update straight away.
Dog Age Calculator FAQ
How do I use the Dog Age Calculator?
Enter dog age and dog size in the fields, then read human age equivalent, life stage and dog years per real year after age 2 in the result panel. The answer updates as you type, and you can press Calculate or Enter to refresh it. Use “Copy link” to share your exact numbers with someone else.
What does the Dog Age Calculator calculate?
Convert dog years to human years by size. It returns human age equivalent, life stage and dog years per real year after age 2 from the 2 values you provide.
What values does the Dog Age Calculator start with?
It opens with dog age 5 years and dog size Medium (9 to 23 kg) so you can see a working result straight away. Replace them with your own numbers, or press Reset to return to these starting values.
Is the Dog Age Calculator free and private?
Yes. It is free, needs no account, and runs in your browser, so nothing you type is sent to or stored on our servers. See the Privacy Policy for details.
Can I rely on the Dog Age Calculator for important decisions?
Treat the result as a well-rounded estimate. Real situations often have details a general calculator cannot know, so confirm important decisions with a qualified professional. See the Disclaimer for more.