Age Calculator
Find your exact age in years, months, and days from your date of birth.
How to use Age Calculator
- Enter your date of birth.
- By default your age is calculated as of today — change the 'Calculate age as of' date to find your age on any other date.
- Your exact age, total days lived, and countdown to your next birthday update instantly.
About this tool
The Age Calculator works out your exact age — in years, months, and days — as of today or any date you choose. It also shows the total number of days and weeks you've been alive, and a countdown to your next birthday. All calculations run instantly in your browser as you type — nothing is uploaded or sent to a server.
Frequently Asked Questions
How is age calculated in years, months, and days?
Starting from your date of birth, we count the number of complete years to the target date, then the number of complete months remaining, then the number of days remaining — the same way you'd count on a calendar, so it correctly accounts for different month lengths and leap years.
Why does my age in days not match years × 365?
Because leap years add an extra day roughly every four years. The total days figure is calculated from the exact calendar dates, not by multiplying years by 365, so it's always precise.
Can I calculate someone's age on a future or past date?
Yes — change the 'Calculate age as of' field to any date. This is useful for figuring out how old someone was at a specific event, or how old they'll be on a future date.