Formula
age = (full years, then full months, then days) between the two dates
- Years and months are counted on the calendar; leftover days are what remains after the last full month.
Count whole years, then whole months, then the days that remain.
Worked example
Born 15 May 1990, on 14 May 2024
- Date of birth
- 1990-05-15
- Age at date
- 2024-05-14
Age
33 years, 11 months, 29 days
Total months: 407
Total weeks: 1,774
Total days: 12,418
How it works
Born on 15 May 1990 and measured on 14 May 2024, a person is 33 years, 11 months and 29 days old — one day short of their 34th birthday. Years and months follow the calendar, so the length of each month is respected rather than assuming 30 days.
People born on 29 February are treated as having their birthday on 28 February in non-leap years. All the arithmetic uses calendar dates only, with no clock times, so your time zone and daylight saving can never shift the answer by a day.
To measure the gap between two other dates use Days Between Dates Calculator, or look ahead with Days Until Calculator. For work history instead of age see Experience Calculator.
Assumptions and limits
- “Today” is your device's local date.
- Dates are Gregorian calendar dates.