← Blogby Marcell Almeida

How to calculate exact age from a birth date

Enter birth date and optional target date — get exact age broken down.

Forms ask for age in years; eligibility rules care about months and days. The Age Calculator computes precise age between any two dates.

Try it — birth date and target date

Open full tool →

How it works

  1. Birth date — date of birth.
  2. Target date — defaults to today; change for historical checks.
  3. Read age — years, months, and days.

Calendar math

Age accounts for varying month lengths and leap years — not just year subtraction.

ISO dates

For ISO 8601 parsing, use the ISO 8601 Date Formatter.

The How to calculate exact age from a birth date is free, runs locally, and never sends your data to a server. More converter tools at maratool.com.