Free online tool

Calculate age from a date of birth

Enter a date of birth and choose the date to calculate against. The result reports full calendar years, months and remaining days, as well as total elapsed days.

Open the interactive Age Calculator

The interactive tool loads in the page. Enable JavaScript to enter data, process content, and download results.

Quick guide

How to use this tool

  1. 01Enter a valid date of birth.
  2. 02Optionally change the reference date from today.
  3. 03Review the calendar age and total elapsed days; future birth dates are rejected.

Capabilities

Features and supported formats

  • Breaks age into years, months and days.
  • Supports a reference date for historical or future-age checks.
  • Uses date-only arithmetic in your browser to avoid time-of-day shifts.

Supported formats

Inputs: calendar dates. Output: years, months, days and total days.

Answers

Frequently asked questions

Does the calculator use today's date?

Yes. The reference date defaults to today on this device, and you can change it to calculate age as of another date.

Is this suitable for legal age verification?

It is a general date calculator, not an identity or legal-age verification service. Follow the rules of the relevant organization or jurisdiction.