Age calculator
Calculate age between a date of birth and a chosen date. See the calendar-based result, calculation steps and date assumptions.
Inputs
Use the units shown—
Enter your values and select Calculate.
Formula & explanation
Age = year difference minus one if the birthday has not occurred
Variables & units
- Date of birth
- Gregorian date
- Age on date
- Gregorian date
Worked example
Born 2000-06-15, on 2026-11-02 the age is 26 completed years.
Assumptions
Gregorian calendar, date-only calculation. For February 29 births this uses March 1 as the anniversary in non-leap years; legal conventions can differ.
Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.
Practice with an example
Use the default input values to find the answer. The reset icon restores those values.
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