Age Calculator
Select a date of birth to calculate the exact age as of today, down to the day.
How the calculation works
The calculator subtracts your birth year, month, and day from today's year, month, and day. When the day or month subtraction goes negative, it borrows from the next unit up — the same way you would if working it out by hand — so results stay accurate across different month lengths and leap years.
Worked example
Someone born on 15 March 2000, calculated on 21 August 2026, is 26 years, 5 months, and 6 days old: 26 full years take you to 15 March 2026, then 5 more months reach 15 August 2026, and the remaining 6 days reach 21 August 2026.
Common uses
- Double-checking age for school, sports, or club eligibility cut-offs
- Working out age for insurance or health-related forms
- Simple curiosity — exact age down to the day
Frequently asked questions
Is this age calculator accurate?
Yes. It calculates the exact difference between two calendar dates, correctly accounting for varying month lengths and leap years.
Can I use this for official documents or age-eligibility checks?
It's suitable for general and planning purposes. For legal, immigration, school-admission, or eligibility contexts, always confirm the exact method required by the relevant authority, since some use different rounding rules.
Can I calculate someone's age on a date other than today?
This tool always calculates age as of today's date. To find age on a specific past or future date, the calculation is the same — simply use that date instead of today's when working it out manually.