Time & Date

Age Calculator

This calculator works out your exact age — or the time between any two dates — down to the day. Enter a birth date and, optionally, a date to calculate to, and get an instant, precise breakdown.

Your age is

— years

Enter your date of birth to calculate.

How the Age formula works

Age is calculated by finding the difference between two calendar dates, then normalizing that difference into whole years, remaining months, and remaining days:

years = endYear − birthYear (adjusted if the birthday hasn't occurred yet this year)
months = endMonth − birthMonth (adjusted for borrowing from years)
days = endDay − birthDay (adjusted for borrowing from months, using the actual days in the prior month)

Because calendar months have different lengths, the calculator borrows days from the correct preceding month rather than assuming a flat 30-day month, which is what keeps the day count accurate.

Step-by-step calculation

Take the end date (today, by default) and the birth date.
Subtract day, month, and year components independently.
If the day difference is negative, borrow days from the previous month using that month's actual length.
If the month difference is negative, borrow 12 months from the year count.
The three remaining values are your age in whole years, months, and days.

Worked example

Someone born on 14 March 1994, measured against 25 July 2026: Years = 2026 − 1994 = 32. Since July 25 is after March 14 in the calendar year, no adjustment is needed. Months = 7 − 3 = 4. Days = 25 − 14 = 11. Result: 32 years, 4 months, 11 days.

Frequently asked questions

Does the calculator account for leap years?

Yes. Because the calculation borrows days using each specific month's real length (including 29 days for February in a leap year), leap years are handled automatically without any special-casing.

Can I calculate the age between two dates that aren't today?

Yes — enter any start date and any end date to get the duration between them, which is useful for anniversaries, contract lengths, or historical date math.

Why does my age in months differ from what I expected?

The calculator reports age as years + remaining months + remaining days, not total months. If you want total months elapsed, multiply the years by 12 and add the remaining months.

Is this calculator accurate for legal age purposes?

The date arithmetic is precise, but legal age of majority rules vary by jurisdiction (some count the day before a birthday as the day someone 'turns' an age). Confirm local rules for legal contexts.