Age Calculator
It calculates exact age or the elapsed duration between two dates in years, months, days, weeks, hours and minutes.
Exact duration
32y 1m 21d
Total months
385
Total weeks
1,677
Total days
11,739
Total hours
281,736
Total minutes
16,904,160
Next birthday in
314 days
What it calculates
It calculates exact age or the elapsed duration between two dates in years, months, days, weeks, hours and minutes.
Why it matters
Calendar arithmetic is unintuitive: months vary in length and leap years break naive day counts.
Who it's for
Anyone completing forms, checking eligibility, tracking milestones or counting down to a date.
Formula
- Start
- Birth date or start date
- End
- Today or a chosen end date
Worked example
Born 14 June 1990, measured on 3 August 2026
- 1Whole years since 14 June 1990: 36
- 2Months since 14 June 2026: 1
- 3Remaining days: 20
36 years, 1 month, 20 days
How the age calculator works
The calculation walks calendar units in order — years, then months, then days — borrowing from the larger unit when needed, so it stays correct across leap years and unequal month lengths.
The duration is calculated on the calendar, not by dividing total days — so a birthday on 29 February and month lengths from 28 to 31 days are handled correctly.
Change the second date to measure any interval: a project deadline, an anniversary, or the gap between two historical dates.
Common mistakes
- Dividing total days by 365 and losing leap days.
- Assuming every month is 30 days.
Tips and best practice
- Use it in reverse to count down to a deadline or event.
- For legal or visa purposes, always confirm against the official definition of the period.
Frequently asked questions
How is age calculated exactly?
By counting complete years from the birth date, then complete months, then remaining days.
How many days between two dates?
The calculator gives total days, weeks, hours and minutes alongside the calendar breakdown.
Does it account for leap years?
Yes. It uses real calendar dates rather than fixed-length approximations.
Why does the day count differ from total days divided by 365?
Because years vary in length. The calculator counts whole calendar years and months first, then the leftover days, which is how ages are stated in practice.
How do you handle a 29 February birthday?
In non-leap years the anniversary is treated as falling on 28 February for counting purposes, which is the most common legal convention.
Can I measure the gap between two past dates?
Yes. Set both dates to whatever you need — the calculator measures any interval, not just an age from a birth date.
Related calculators
Methodology & trust
- Formula source
- Gregorian calendar date arithmetic.
- Last updated
- 2026-07-28
- Privacy
- Every calculation runs in your browser. No inputs are sent to a server or stored.
- Accessibility
- Keyboard navigable, labeled inputs and WCAG AA color contrast.