Computes exact age in years, months, and days from a given birth date relative to any target date. Numbers never leave your device — every calculation runs locally in your browser.
Runs on date-fns
Content reviewed October 2026 · About Toolzum
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It computes your exact age in years, months, and days by comparing your date of birth to a target date. If you leave the target date untouched, it defaults to today. The calculation handles month lengths correctly — for example, if today is the 15th and your birthday falls on the 31st, it borrows days from the previous month so the result always reflects calendar reality rather than simple subtraction.
Yes. Set any date in the 'Target Date' field — for example a future event, a past signing date, or a deadline — and the tool returns your exact age as of that date. This is useful for age eligibility checks, contract dates, or anniversary calculations.
Yes. Because the tool works with calendar dates rather than fixed 365-day years, February 29th and leap-day birthdays are handled naturally. If your target date is not a leap year, the day count borrows from the actual length of the preceding month.
The tool blocks it: entering a target date before the date of birth shows the error 'Target date must be on or after the date of birth' and clears the result. Swap the dates so birth comes first, then press Calculate Exact Age again.
No. The calculation runs entirely in your browser — your date of birth never leaves your device and nothing is stored or uploaded. This tool is fully private and works offline after the page loads.
Born 31 Jan 2000 with target 15 Feb 2026 gives 26 years, 0 months, 15 days: the 15 − 31 day deficit borrows January’s 31 days, then months normalize. Flip the dates and you get the ‘Target date must be on or after the date of birth’ error instead of a result.
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