Age Calculator

Calculate exact age from date of birth: years, months and days, plus total days lived, day of the week you were born and days until your next birthday.

How exact age is calculated

Age is measured in complete calendar units: full years first, then full months since the last birthday, then the days left over. Because months have different lengths and leap years exist, this is a calendar walk rather than a division — which is why this result matches how ages are stated on official documents.

Worked example

Born 15 March 2000, age on 19 July 2026: the last birthday was 15 March 2026 (26 full years), 15 March → 15 July is 4 full months, and 15 → 19 July is 4 days: 26 years, 4 months, 4 days — about 9,622 total days.

Common uses

Frequently asked questions

How does the age calculator work?
It counts complete calendar years from your date of birth, then complete months, then the remaining days — the same way ages are stated officially. It also totals your age in months, weeks, days and hours.
How are leap years handled?
The calculation walks the real calendar, so leap days are counted naturally. If you were born on 29 February, your age in years increases on 1 March in non-leap years.
Why does my age in days not equal years × 365?
Because leap years add a day roughly every four years. Someone exactly 24 years old has lived about 8,766 days, not 8,760.
Can I calculate age at a date other than today?
Yes — change the "Age at date" field to any date, past or future, to get the age on that day (useful for forms, school cut-offs and eligibility rules).