Age Calculator

About this calculator

A free age calculator that works out an exact age from a date of birth. It reports age the way people say it — years, months, and days — and also as running totals of months, weeks, and days for forms and milestones. By default it measures age as of today, but you can set any reference date to find age on a past or future day. The calculation uses whole calendar days and accounts for leap years, so the result is precise. The birth date is processed in your browser and never stored.

How exact age is calculated

Age is the calendar span from a birth date to a reference date, broken into full years, then full months, then leftover days. The tricky part is that months vary in length, so the calculator borrows days from the actual preceding month rather than assuming 30. That is why its years-months-days answer matches how a person would count it by hand, including across a leap day.

The same span is also shown as total months, total weeks, and total days. Those totals are handy for baby milestones ("16 weeks"), official forms that ask for age in months, or any situation where a single running number is easier than a years-months-days breakdown.

Age today or on any date

By default the reference date is today, so you get current age. Change it to a future date to answer "how old will I be then" — useful for eligibility cut- offs like school enrolment, licences, or retirement dates — or to a past date to find how old someone was at a particular event.

Everything is anchored to whole calendar days, so timezones and daylight saving never shift the result, and a birth date later than the reference date returns a zeroed age rather than a negative number.

By variant

• Age in Days
• Age on a Specific Date

Questions

Is the age calculator free and private?

Yes. It is free, needs no account, and runs entirely in your browser. The birth date you enter is never uploaded or stored.

How is exact age calculated?

As full years, then full months, then leftover days between the birth date and the reference date, borrowing from the real length of each month so leap years and uneven months are handled correctly.

Can I find my age on a future or past date?

Yes. Change the reference date from today to any future date to see how old you will be, or to a past date to see how old you were then.

Does it count leap years?

Yes. The calculation uses actual calendar days including leap days, so the years-months-days result and the day totals are accurate.