Find out your exact age in days — or the gap between any two dates. Handles leap years correctly using the Gregorian calendar. No accounts, no tracking.
The calculator subtracts your start date from the end date and reports the result in several units. Years, months and days are computed by walking the calendar (taking into account that February has 28 or 29 days), so the answer matches what a person would say (for example "33 years, 2 months and 5 days"). Days, weeks, hours, minutes and seconds are simple multiplications of the total elapsed milliseconds. Leap years are handled by the browser's Date object, which follows the Gregorian calendar used in the UK since 1752.
To the day, assuming both dates are in the same timezone. The calculator uses your browser's clock and assumes the UK Gregorian calendar (in use since 1752). Crossing daylight saving boundaries can shift the total by an hour but not by a day.
It walks the calendar in whole years, then whole months, then leftover days. So if you were born on 5 March 1990 and today is 21 May 2026, the result is 36 years, 2 months and 16 days. We borrow days from the previous month if needed (so 30 April + 2 months gives 30 June, not 1 July).
Yes. Switch to the "Days between two dates" mode and enter both. Useful for wedding anniversaries, project deadlines, sober-since counters, or how long until your next holiday.
ageindays.co.uk is a free, browser-based age calculator that converts any date of birth — or any two dates — into an exact count of days, weeks, months, and years. It is built for people who need a precise answer quickly: checking passport validity windows, calculating contract durations, verifying age-related eligibility criteria, or satisfying curiosity. The tool runs entirely in your browser and produces results instantly with no server involved.
A simple, accessible age and date-difference calculator. The page does everything in your browser - we never receive or store the date you typed. No account, no email list, no tracking beyond Google Analytics 4 with Consent Mode v2 (you can reject all cookies and the page still works).
For guidance only. This tool does not constitute professional advice. If your situation is complex, speak to a qualified professional.
Last reviewed: 21 May 2026.
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