Age Calculator

How the age calculator works

Your age is counted forward from your date of birth in three steps: first whole years, then whole months, then the days that are left. The calculator does exactly what you would do with a calendar, just without the mistakes.

It works with dates only, never times of day, so the answer is the same in every time zone and is not thrown off by daylight saving time.

Worked example

Say you were born on 15 May 1990 and want your age on 21 October 2026.

1. Years: from 15 May 1990 to 15 May 2026 is 36 years.
2. Months: from 15 May 2026 to 15 October 2026 is 5 months.
3. Days: from 15 October to 21 October is 6 days.

So you are 36 years, 5 months and 6 days old. Counted another way, that is 13,308 days, or 1,901 weeks and 1 day, or 319,392 hours. Your next birthday, your 37th, falls on Saturday, 15 May 2027, which is 206 days away.

Month ends and leap years

Most of the time the method above is obvious. The tricky cases are birthdays on the 29th, 30th or 31st, because not every month has those days. The rule used here is the one many legal and banking systems use for adding months: if the day does not exist, the month ends on the last day of that month.

If you were born on 29 February, the calculator shows an extra option. By default your birthday in common years falls on 28 February. Switch it to 1 March if you need the rule that some countries use for legal age. The difference only matters for one day every few years, but it can decide whether you are old enough on a deadline.

Age limits for exams and jobs

Government recruitment, entrance exams and some admissions state an age limit “as on” a fixed date, for example 21 to 32 years as on 1 August 2026. What counts is your age on that cut-off date, not on the day you apply.

Two points catch people out:

• A maximum age is usually “not yet reached the next birthday”. A limit of 32 normally means you must not have turned 33 by the cut-off date. Someone who is 32 years and 11 months old still qualifies.
• The limit is easier to read as a range of birth dates. For 21 to 32 years as on 1 August 2026, anyone born from 2 August 1993 to 1 August 2005, both dates included, meets the limit.

Open Check an age limit under the calculator, enter the minimum and maximum, and set the cut-off as the Age on this date. You will see whether you qualify and the exact range of birth dates allowed. Many notices give extra years to certain groups, so always read the official notice for relaxations.

What the totals mean

• Months, weeks and days are counted from your date of birth to the chosen date. The leftover days are shown separately, so 437 months and 6 days is exact.
• Hours and minutes multiply the days by 24 and by 1,440. They count from midnight to midnight because the calculator does not ask for your time of birth.
• Decimal age is useful for forms and research that want one number. It divides the days since your last birthday by the length of your current birthday year, so 36.44 means you are a little under halfway to 37.

Tips

• Check a future date. Put any later date in “Age on this date” to see how old you will be at a wedding, a graduation or a retirement date.
• Count days between other events. For gaps that are not about a birthday, like a notice period or a project deadline, the date calculator also counts business days and can add or subtract days from a date.
• Work with hours and minutes. To add up shift lengths or time between two clock times, use the time calculator.
• Children and BMI. For children and teens, BMI is read against age, so exact age matters. Adults can use the BMI calculator directly.
• Want to check it by hand? Our guide on how to calculate your exact age walks through the method step by step, including leap-day birthdays.

Everything runs in your browser. Your date of birth is not saved or sent anywhere.