Date & Time

Age Calculator

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Use this age calculator for a clear date & time estimate. Results update instantly in your browser.

What this calculator does

Calculate age from a birth date and a reference date.

How to use this calculator

  1. Enter date of birth and the date to calculate against.
  2. Review the calculation assumptions before using the result.
  3. The result gives completed years and the remaining months and days.

How to calculate

Age is the calendar difference between birth date and calculation date; total units derive from the exact elapsed days.

Choose the calculation mode where available, then enter the values requested by the age calculator. Results update immediately.

Worked example

The defaults provide a complete worked example. Change any value to recalculate the result and any schedule shown.

Understanding your result

The result gives completed years and the remaining months and days.

  • Time-zone and inclusive-date rules can differ in legal contexts.
  • Double-check values and units before calculating.

Frequently asked questions

What does this age calculator do?

Calculate age from a birth date and a reference date.

How do I use this age calculator?

Enter date of birth and the date to calculate against.

What does the result mean?

The result gives completed years and the remaining months and days.

What should I check before relying on it?

Time-zone and inclusive-date rules can differ in legal contexts.

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