Age Calculator — Exact to the Day
Find your exact age in years, months, and days — or the age at any date — with total weeks and days, and a countdown to your next birthday.
Curious how age is counted differently around the world, or how leap-day birthdays work legally? Read the age calculation guide
Frequently Asked Questions
How does the calculator get years, months, and days exactly right?▼
It subtracts calendar components rather than dividing total days by averages. When the day-of-month goes negative it borrows the real length of the previous month (28, 29, 30, or 31 days), and when months go negative it borrows 12 months from the years. That is why the result matches how people actually state ages.
Can I calculate age at a past or future date, not just today?▼
Yes. Fill in the optional "Age at date" field with any date — a form deadline, an exam cutoff, a historical date — and the age is computed as of that day. Leave it blank to use today.
How are leap years handled?▼
February 29 is treated as a real calendar day, so day counts across leap years are exact. If you were born on Feb 29, the next-birthday countdown targets Feb 29 in leap years and Feb 28 in other years — the most common legal convention.
Why do total days and "years, months, days" not convert neatly into each other?▼
Because months have different lengths, "3 months" can mean 89 to 92 days depending on which months they are. The calculator therefore shows both: the calendar-correct breakdown and the precise totals in months, weeks, and days.
Is my date of birth sent to a server?▼
No. Everything is computed in your browser with plain JavaScript date arithmetic — no uploads, no analytics on your inputs, no account. It also keeps working offline once the page is loaded.