Age Calculator

Exact age in years, months and days — plus total weeks, days and hours, and your next birthday.

About the Age calculator

This age calculator works out exactly how old someone is on any date. Enter a date of birth and it returns the age in years, months and days, the same way you would say it out loud: "36 years, 4 months, 9 days".

It also gives the age as total months, weeks, days and hours, tells you which day of the week the person was born on, and counts down to the next birthday. Change the second date to see how old someone was on a past date or will be on a future one.

How to use it

Enter the Date of birth.
Leave Age on set to today, or pick another date to find the age on that day.
Read the age in years, months and days at the top of the result.
Check the rows below for total months, weeks, days and hours, the weekday of birth and the next birthday.

The formula

Age is counted on the calendar, not by dividing days by 365. The calculator compares the two dates part by part:

Years: the difference between the two years, minus one if the birthday hasn't arrived yet in the final year.
Months: the whole months left over after those years.
Days: the days left after the whole months. If the day of the month on the "age on" date is smaller than the birth day, it borrows the length of the previous month (28, 29, 30 or 31 days).

The totals are simpler:

total days = age-on date − birth date
total months = years × 12 + months
total weeks = total days ÷ 7 (whole weeks plus leftover days)
total hours ≈ total days × 24

Leap days are included automatically because real calendar dates are used.
Hours are approximate because the calculator doesn't know the time of day you were born.

Worked example

Say someone was born on 15 June 1990 and you want their age on 24 October 2026.

From June 1990 to June 2026 is 36 whole years.
From 15 June to 15 October 2026 adds 4 whole months.
From 15 October to 24 October adds 9 days.

So the age is 36 years, 4 months, 9 days. Counted another way, that is 436 months, or 13,280 days, which is 1,897 weeks and 1 day, or roughly 318,720 hours. 15 June 1990 was a Friday. The next birthday, 15 June 2027, is 234 days away.

This is the same kind of answer you would give on a form that asks for age in years and months, such as for a child's school entry or a medical record. For just the gap between any two dates, the days between dates calculator also shows business days and weekend days.

Leap-day birthdays and uneven months

Months have different lengths, so an age in months and days can look a little uneven near the end of a month. When the day count needs to borrow, the calculator uses the length of the month just before the "age on" date. This matches the way most people count a birthday-based age by hand.

People born on 29 February only get a real birthday in leap years. In other years, this calculator shows the next birthday as 1 March, which is the first day after 28 February. Many people celebrate on 28 February instead, and legal rules about when a leap-day birth counts as a year older can differ by country. Your age in whole years is unaffected, because it only changes once the birthday date has passed.

Frequently asked questions

How do I calculate my age in days?

Subtract your birth date from today's date counting every calendar day. The Total days row does this for you, including every 29 February you have lived through.

How old am I if I was born in 2000?

It depends on whether your birthday has passed this year. In 2026 you are 26 once your birthday has come, and 25 before it. Enter your full date of birth for the exact answer.

What day of the week was I born on?

The Born on a row shows it. You can also check any single date with the day of the week calculator.

Can I find my age on a future date?

Yes. Set Age on to any future date, such as a retirement date or a birthday party, and the calculator shows how old you will be then. The date must be on or after the date of birth.

Why are the total hours only approximate?

The calculator multiplies whole days by 24. It doesn't know what time you were born, and it ignores clock changes for daylight saving time, so the real figure can be off by up to a day's worth of hours.

Last updated October 24, 2026. Results are estimates for education and planning — see our disclaimer.