Age Calculator

Enter a date of birth to calculate age in completed years, months, and days as of today on your device, plus total days and weeks.

Date of birth

Select a date of birth and click Calculate Age.

How to calculate an age

Select a date of birth in the date field.
Select Calculate Age.
Read the calendar age and the totals below it. The end date is today's local calendar date on your device.

Worked example: reading calendar age

For a birth date of 15 June 2000, the age on 20 August 2026 is 26 years, 2 months, and 5 days. This example uses a fixed reference date; the live tool calculates against today, so its result changes as time passes.

Completed years count anniversaries. Remaining months and days describe the portion since the last anniversary; they are not calculated by dividing total days by 365 or 30.

Month-end rules and limitations

Calendar months have different lengths. This calculator clamps an anniversary to the last available day of a shorter month: 31 January to 28 February counts as one month in a non-leap year. A 29 February birthday uses 28 February for its anniversary in a non-leap year.

The tool accepts a birth date, not a birth time or birthplace timezone. It uses your device's current local date and is intended for calendar calculations. A service or official process may apply a different anniversary convention or cutoff date.

Frequently asked questions

Can I calculate age on a future or past reference date?

This tool always uses today. Date Difference Calculator can compare two selected dates, but its result is elapsed time rather than calendar years and months.

Why are total weeks rounded down?

Total weeks counts complete seven-day periods. Any remaining days are included in total days but do not create another complete week.

What if I enter a future birth date?

The tool rejects it and asks for a date that is not in the future.