Age Calculator
Calculate your exact age — not an approximation — from your date of birth: full years, remaining months and days, total days lived, and a countdown to your next birthday.
Type your birth date as year-month-day.
Leave blank to use today.
Enter your values to see the result.
How it works
This calculator measures age the way birth certificates and official forms do: it counts complete calendar years first, then the leftover whole months, then the remaining days. Every month is measured at its real length — 28, 29, 30, or 31 days — and leap years are handled by the actual Gregorian rules, so there is no drift around February or month boundaries. You get far more precise results than the 365.25-day-per-year shortcut many sites take. Want to know how old you were on a specific date — a graduation, a historic landing, the day a contract was signed? Fill in the optional “age at” field with that date; leave it blank and today is used automatically. Birthdays on February 29 are treated fairly too: in non-leap years the anniversary anchors to the last day of February rather than sliding into March. Everything runs locally in your browser — your dates are never sent anywhere and nothing is stored.
Frequently asked questions
How is my age calculated exactly?
The calculator counts complete calendar years between your birth date and the target date, then the whole months left over, then the remaining days — using each month’s true length, leap years included. For example, someone born on 1990-08-15 turns 35 only on 2035-08-15, and the months in between are counted as real calendar months, not fixed 30-day blocks.
Why does my age differ slightly from other websites?
Many age tools divide the total time by an average year of 365.25 days. That shortcut drifts by a day around leap years and uneven month lengths, so two sites can disagree. This calculator counts actual calendar years, months, and days — the same method used on official documents — so the result matches your records.
How do I see how old I was on a specific date?
Enter your date of birth as usual, then type the date you are curious about into the “Age at date (optional)” box — for example the day you graduated or a famous historical event. Leave that box blank and today’s date is used. Past and future dates both work, so you can also check how old you will be at a planned retirement date.
What about February 29 birthdays?
Leap-day birthdays are anchored to the end of the month: in common years the anniversary is counted on February 28 rather than drifting into March 1 or being skipped. The next-birthday countdown follows the same rule, and the years-months-days age stays calendar-exact either way.