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Date & time

Age calculator

Find completed years of age and elapsed calendar days between a birth date and a reference date.

Free & no registration Calculated in your browser
01

Your inputs

The starting values are an example.

Decimals: 12.5 · Thousands: 1,234.56. Follow the field instructions for lists.

02

Your result

Enter your values and select Calculate.

Your calculation will appear here.

Your result will include the relevant values and units.

Understand the calculation

Formula and example

How it is calculated

Completed years = year difference minus one if the birthday has not yet occurred by the reference date

Worked example

From 15 June 1990 to 14 June 2026, 35 complete years have passed. On 15 June, the age is 36.

Things to check

  • For a birthday on 29 February, the anniversary is treated as 1 March in a non-leap year. This calculation convention does not replace legal age or deadline rules.