ToolWren › Age

Age Calculator

Find an exact age in years, months and days from any birth date, with totals in days, weeks and months and a countdown to the next birthday. All math runs in your browser.

100% client-side · nothing is uploaded

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How to use the Age

Pick your date of birth.
Optionally set an age as of date — leave it blank to use today.
Read your exact age in years, months and days, plus totals and a next-birthday countdown.
Change either date to recalculate instantly.

Privacy: this tool runs entirely in your browser. Your input is never sent to, received by, or stored on any server — there are no uploads and no tracking of what you enter.

About Age

Exact age, not just years

Subtracting years alone is misleading near a birthday. This calculator does proper calendar math, borrowing days and months so the result is accurate to the day.

Totals and milestones

Besides the year/month/day breakdown, you get the total number of days, weeks and months lived — handy for milestones like a 10,000-day celebration.

Age as of any date

Leave the second field blank to use today, or set it to compute someone's age on a specific past or future date.

Frequently asked questions

How is age calculated exactly?

The tool subtracts the dates calendar-correctly, accounting for differing month lengths and leap years.

Can I calculate age on a future date?

Yes — set the "age as of" field to any date.

Does it handle leap-year birthdays?

Yes; Feb 29 birthdays are handled by the underlying date arithmetic.