Age Calculator
Not just “how many years” — the exact figure in years, months and days, the total number of days, and how long until the next birthday, between any two dates you choose.
Your numbers
Leave as today, or pick any past or future date — a school cut-off, a race category deadline, a retirement date.
Result
How it works
Exact age is a borrowing exercise, the same one you learned for subtraction at school: if the day-of-month hasn’t been reached yet, borrow a month; if the month hasn’t been reached, borrow a year. The calculator does the borrowing against the real calendar, including the variable length of months — which is why “months” in an exact age can mean 28 to 31 days depending on which months they are.
The total-days figure ignores all of that and counts raw midnights, which is the number that matters for things like eligibility windows counted in days and the quietly startling fact that a 30-year-old has lived about 11,000 of them.
Good practice & limits
- For official forms, age is usually age at last birthday — the years figure — unless the form asks for the exact date another way.
- School and sport categories often use age on a fixed date (1 September, 31 December), not age on the day. Set the second date to that cut-off.
- Leap-day birthdays: most systems treat 1 March as the birthday in non-leap years. Families remain divided.