# Dog and Cat Age in Human Years Calculator

Convert your dog’s or cat’s age to human years with the formula from a 2020 study, not the old seven-year rule.

- URL: https://toolstackhub.co.uk/tools/dog-and-cat-age-in-human-years-calculator/
- Category: Calculators
- Price: free, no sign-up
- Privacy: runs in the browser; input is not uploaded
- Last updated: 2026-10-08

## About
The old rule of multiplying a dog’s age by seven is not accurate. This calculator uses a formula from a 2020 study of changes in DNA with age in Labrador retrievers: human age ≈ 16 × ln(dog age in years) + 31. For cats it uses the widely used guide of 15 human years at age one, 24 at age two, and four more for every year after that. Dogs of different breeds age at different rates, so treat the result as a fun, rough guide.

## How to use
1. Choose dog or cat.
2. Enter your pet’s age in years and extra months.
3. Read the equivalent human age and the age chart.

## FAQ
**How old is a 5-year-old dog in human years?** Using the 2020 formula, about 57. The old seven-year rule would say 35.

**Is the dog year rule of 7 true?** No. Dogs mature quickly in their first years and then age more slowly, so a simple multiple is not accurate.

**How old is a 10-year-old cat in human years?** About 56 by the common guide.

**Is the Dog and Cat Age in Human Years Calculator free?** Yes, with no sign-up or limits.