Age Calculator
Exact age down to the minute, plus the countdown to the next birthday.
Defaults to today. Change it to work out an age on any past or future date.
Adding a birth time makes the hours and minutes figures exact rather than approximate.
Exact age
—
- Day of the week born—
- Next birthday—
- Days until next birthday—
- Leap days lived through—
- 10,000-day anniversary—
What the age Calculator does
Age looks like simple subtraction and is not, because months have different lengths. The correct approach — and the one this calculator uses — is to subtract the calendar components separately and borrow when a component goes negative, using the actual length of the preceding month rather than an average.
An example makes the difference clear. From 31 January to 1 March, a naive calculation gives one month and one day. Borrowing correctly gives one month and one day only if February had 29 days; in a common year it gives one month and one day from 31 January to 3 March instead. The distinction matters for anything where an exact age determines eligibility.
Alongside the years-months-days figure, the calculator reports cumulative totals: months, weeks, days, hours and minutes lived. These come from the raw millisecond difference and are exact. If you enter a time of birth the hour and minute figures become genuinely precise; without one they are measured from midnight.
The extras answer the questions people usually ask next: which day of the week you were born, when your next birthday falls and how far away it is, how many 29 Februarys you have lived through, and the date of your 10,000-day anniversary — which arrives at about 27 years and four months and tends to pass unnoticed.
You can also change the second date to work out an age on any past or future day, which is what you need for “how old will she be at the wedding?” or “how old was he when this photograph was taken?”
How to use it
- Enter the date of birth.
- Leave the second date as today, or set it to any past or future date to get the age on that day.
- Add a time of birth if you want the hours and minutes to be exact.
- Read the headline figure for the calendar age and the tiles below for cumulative totals.
A worked example
For someone born on 17 March 1994, calculated on 6 September 2026:
| Exact age | 32 years, 5 months, 20 days |
| Total months | 389 |
| Total days | 11,861 |
| Total hours | 284,664 |
| Born on a | Thursday |
| Next birthday | Wednesday, 17 March 2027 — 192 days away |
| Leap days lived through | 8 |
Note the months figure. 389 months is not 32.4 × 12 rounded — it is the count of completed calendar months, which is what a lender, an insurer or a school admissions form means when it asks for age in months.
Frequently asked questions
How is age calculated when someone is born on 29 February?
This calculator uses the calendar-component method, which in common years treats 1 March as the day the age increments — the convention most English-speaking jurisdictions follow. Some countries use 28 February instead. If the answer has legal consequences, check the rule that applies where you are.
Why does the total-months figure not match years times twelve?
Because it counts completed calendar months, including the part-year. Someone aged 32 years and 5 months has lived 389 complete months, not 384. That is the figure official forms usually want.
Does it account for time zones?
It uses your device's local time zone throughout. If a birth happened in a different time zone from the one your device is set to, the hours and minutes totals can be out by up to a day's worth of offset. The years-months-days figure is unaffected in almost every case.
Can I use this for a legal or medical purpose?
No. It is a calendar calculation for general information. Legal definitions of age vary by jurisdiction, particularly around leap days, time zones and the exact moment an age is attained. For anything with legal or medical consequences, use the definition that applies in that context.