Age Calculator Between Two Dates
The exact time between any two dates, broken into years, months and days, with the totals in months, weeks, days and hours underneath. Leap years are counted properly, and the result updates as you type.
How the age between two dates is calculated
An exact age is not just a count of days. It is expressed the way people and official forms express it: whole years first, then whole months, then the days left over. This calculator follows that method precisely:
- Count the whole months between the two dates. If the end day-of-month is smaller than the start day-of-month, the last month is not complete yet, so one month is held back.
- Anchor the start date that many whole months forward. If the anchor month is shorter than the start day (for example, starting on January 31 and landing in February), the anchor lands on that month's last day instead.
- Count the remaining days from the anchor to the end date. Those are the leftover days.
- Split the months into years and months: every 12 whole months become one year.
The totals underneath the main answer come straight from the calendar: total days is the exact number of midnights between the two dates (leap days included), and weeks, hours and minutes are worked out from that count.
Worked example: 15 January 2000 to 30 October 2026
Take someone born on Saturday, 15 January 2000, and measure their age on Friday, 30 October 2026:
- Whole months from January 2000 to October 2026: 321 (the end day, 30, is after the start day, 15, so the last month is complete).
- Anchor date: 15 January 2000 + 321 months = 15 October 2026.
- Leftover days from 15 October to 30 October: 15 days.
- 321 months = 26 years and 9 months.
So the exact age is 26 years, 9 months, 15 days. The same span in every unit:
| Unit | Value |
|---|---|
| Years, months, days | 26 years, 9 months, 15 days |
| Total months | 321 months |
| Total weeks | 1,397 weeks and 6 days |
| Total days | 9,785 days |
| Total hours | 234,840 hours |
| Total minutes | 14,090,400 minutes |
Leap years and February 29 birthdays
A year is a leap year when it divides by 4, except century years, which must divide by 400: 2000 was a leap year, 1900 was not, 2024 was, 2026 is not. Leap years matter here because every February 29 inside your date range is a real day, and it is counted in the total days.
For a person born on February 29, whole-month steps land on February 28 in ordinary years (the anchor rule above), which is how most legal systems treat a leap-day birthday in a non-leap year. From 29 February 2024 to 28 February 2025 the difference is 0 years, 11 months, 30 days, and it reaches a full year on 1 March 2025 by this reckoning. Some countries and forms celebrate the birthday on February 28 instead, so for official paperwork, check the rule that applies to your document.
When to include the end date
Plain date difference treats the end date as the morning of that day: Monday to Tuesday is 1 day. Counting things like a stay, a hire period or a notice period often includes both the first and the last day. The “include the end date” option adds exactly one day for those cases, and the result note tells you when it is on.