Age calculator
The age calculator subtracts a date of birth from an “age on” date and reports whole years, then whole months, then leftover days, together with total days lived and the date of the next birthday. Nothing you enter leaves your browser.
Age on Tue, Oct 27, 2026
36 years, 9 months, 26 days
| Born on | Monday, January 1, 1990 |
|---|---|
| Total days | 13,448 |
| Total weeks | 1,921 |
| Total months | 441 |
| Next birthday | Friday, January 1, 2027, in 66 days |
How to use it
- Enter the date of birth.
- Leave “age on” as today, or pick another date.
- Read the exact age and the next birthday.
Questions
How is exact age calculated?
Whole years are counted to the latest birthday, then whole months, then the days left over. Birthdays on February 29 are treated as February 28 in non-leap years.
Is my date of birth stored?
No. The calculation runs in your browser and nothing is sent to or saved on a server.
Can I find how old someone was on a past date?
Yes. Set the “age on” date to the past date.
Last reviewed 2026-10-27. Calculations use the proleptic Gregorian calendar in UTC, so daylight saving time never shifts a result. Other calculators: Date calculator, Days between dates, Business days calculator.