Enter Date of birth and Age on date to review age with this tool. Calendar age counts birthdays and calendar boundaries rather than dividing elapsed days by 365.
Enter a valid date of birth.
Age = Current date − Date of birth, adjusted for whether the birthday has occurred this year.The calculation links Date of birth and Age on date to age. Calendar age counts birthdays and calendar boundaries rather than dividing elapsed days by 365. A leap-year birthday can require a particular anniversary convention.
Enter Date of birth and Age on date to review age with this tool. Calendar age counts birthdays and calendar boundaries rather than dividing elapsed days by 365.
Calculate completed years and the remaining calendar interval between a birth date and a comparison date. Use a chosen comparison date for an application or anniversary.
Calendar age counts birthdays and calendar boundaries rather than dividing elapsed days by 365. A leap-year birthday can require a particular anniversary convention.
Prepare Date of birth and Age on date. Enter the birth date and the intended comparison date; check that the comparison is not earlier than birth.
Calendar age counts birthdays and calendar boundaries rather than dividing elapsed days by 365. A leap-year birthday can require a particular anniversary convention. Legal eligibility and official age rules may define the effective date differently. Date-only arithmetic does not include birth time or time-zone differences.
Use the full settings in the worked-example table. They produce Age: 30 years, 0 months, 0 days. Compare the method and units as well as the displayed number.
The displayed relationship is Age = Current date − Date of birth, adjusted for whether the birthday has occurred this year. Enter the birth date and the intended comparison date; check that the comparison is not earlier than birth.
Legal eligibility and official age rules may define the effective date differently. Date-only arithmetic does not include birth time or time-zone differences. Check the original measurement, source data and the convention required by the task.
Worked age calculator example. Set Date of birth = 1996-10-20; Age on date = 2026-10-20. The corresponding output is Age: 30 years, 0 months, 0 days. Calendar age counts birthdays and calendar boundaries rather than dividing elapsed days by 365.
Calculate completed years and the remaining calendar interval between a birth date and a comparison date. Use a chosen comparison date for an application or anniversary.
Enter the birth date and the intended comparison date; check that the comparison is not earlier than birth.
| Field | Example value | Entry check |
|---|---|---|
| Date of birth | 1996-10-20 | Use the calendar date for this scenario; keep the comparison date explicit. |
| Age on date | 2026-10-20 | Use the calendar date for this scenario; keep the comparison date explicit. |
Relationship used for this example: Age = Current date − Date of birth, adjusted for whether the birthday has occurred this year.
Calendar age counts birthdays and calendar boundaries rather than dividing elapsed days by 365. A leap-year birthday can require a particular anniversary convention.
| Output | Displayed result |
|---|---|
| Age | 30 years, 0 months, 0 days |
With these settings, age is 30 years, 0 months, 0 days. Use the same units and calculation mode when reproducing this example.
Calendar age counts birthdays and calendar boundaries rather than dividing elapsed days by 365. A leap-year birthday can require a particular anniversary convention. Legal eligibility and official age rules may define the effective date differently. Date-only arithmetic does not include birth time or time-zone differences.
Replace the illustrative date of birth value (1996-10-20) with your own value, then complete the other inputs for the same scenario. Enter the birth date and the intended comparison date; check that the comparison is not earlier than birth.