Age Calculator

Enter a date of birth. The “age at” date defaults to today, but you can set any date — for example to find someone’s age on a past or future day.

Calculate age

Enter your values and select Calculate to see the result.

How age is counted

Age is counted in completed years, then completed months, then remaining days. A person born on 15 June 1990 turns 36 on 15 June 2026; the day before, they are 35 years, 11 months and some days old. Months are stepped on the calendar — not averaged at 30.44 days — so results match how people normally state age.

Worked example

Born 1990-06-15, age on 2026-09-27

  1. Whole years: 15 June 1990 → 15 June 2026 = 36 years
  2. Whole months: 15 June → 15 September = 3 months
  3. Remaining days: 15 September → 27 September = 12 days

36 years, 3 months, 12 days.

Leap-day birthdays

Someone born on 29 February has a calendar birthday only in leap years. This calculator treats 28 February as the birthday in other years. Laws differ — some jurisdictions use 1 March for legal age — so check local rules where it matters.