Free age calculator — exact age in years, months, and days
Work out how old someone is from their date of birth, or their age as of any past or future date. This free online age calculator gives a calendar-accurate breakdown in years, months, and days — not a rough total-days-divided-by-365 estimate — and counts the days left until the next birthday.
How to calculate age from a date of birth
- Pick the Date of birth in the first date field.
- Leave the As of field on today's date, or set any reference date — a form deadline, an admission cut-off, or a future anniversary.
- Click Calculate age.
- Read the Years, Months, and Days cards, plus the countdown to the next birthday underneath.
What people use an age calculator for
- Forms, KYC, and insurance — confirm completed age on the day a document is signed.
- School admissions and exams — check eligibility as on a fixed cut-off date.
- Job and scholarship applications — verify an age limit before applying.
- Birthdays and anniversaries — see exactly how many days remain.
How exact age is worked out
Age is measured the way a calendar works: the tool subtracts day, month, and year separately, borrowing from the previous month when the birth day has not come round yet, so a month always means a real month, whether 28, 30, or 31 days. Leap years are handled too, and a 29 February birthday falls back to 28 February in non-leap years when counting to the next one. If the date of birth is later than the as-of date, an error appears instead of a negative age.
Private by design — nothing leaves your browser
Both dates stay on your device: the calculation runs in JavaScript, so no date of birth is uploaded, logged, or stored. Working with epoch values instead? Use the Unix timestamp converter, or convert measurements with the unit converter.
Need a custom tool or internal utility built for your team? Get in touch with SR Infobiz.