Age calculator
Work out an exact age, and how long until the next birthday.
- Runs in your browser — nothing you enter is uploaded
- No sign-up, no quotas, free to use as often as you like
How it works
Age looks trivial until you have to be exact about it — a form that wants years and months, a visa rule with a cut-off date, a legal threshold, a child's age in weeks. Counting it by hand is easy to get wrong, mostly because months are different lengths and February moves.
How the age is counted
Whole years first, then whole months, then the days left over — which is how people actually say their age. Borrowing is handled correctly: when the day of the month has not yet come round, a month is borrowed and the right number of days for that month is added, rather than a flat thirty.
Leap years are handled
The totals are worked out from the real calendar, so leap days are counted where they fall. Someone born on 29 February is treated as having their birthday on 1 March in common years, which is the ordinary convention.
The other totals
Months, weeks, days and hours are given as running totals since birth. These are the figures forms want for infants, and the ones people are curious about for themselves.
It uses your device's clock
“Today” comes from your own computer, so the answer reflects your time zone and is only as accurate as your clock.
Age calculator — questions
Does it handle leap years?
Yes. Totals come from the real calendar, so leap days are counted where they fall.
How is the age counted?
Whole years, then whole months, then the days left over — the way people normally state an age.
What about birthdays on 29 February?
In common years the birthday is treated as 1 March, which is the usual convention.
Is my date of birth sent anywhere?
No. The calculation happens in the page and nothing is stored.