Age calculator

Enter your date of birth to find your exact age in years, months, and days. You’ll also see how many days are left until your next birthday.

Select your birth date
Leave blank to use today’s date
Your age —

How this age calculator works

Age is calculated by comparing your date of birth to a reference date (today by default). The result is broken down into whole years, then remaining whole months, then remaining days. This matches how age is commonly expressed in everyday conversation.

For example, if you were born on 15 March 1990 and today is 10 June 2025, you are 35 years, 2 months, and 26 days old. The calculator also counts the total number of days you’ve been alive and shows when your next birthday falls.

Good to know

  • Dates are based on your device’s local time zone.
  • Leap years are handled automatically. A person born on 29 February will have their age calculated relative to 28 February (or 1 March) in non-leap years, depending on the reference date.
  • The “as of” date lets you calculate age at any point in the past or future — useful for forms, planning, or curiosity.
  • All calculations run in your browser. No date of birth is sent anywhere.

Frequently asked questions

Why does my age in months sometimes look off by one?

Months are counted as full calendar months. If the current day of the month is earlier than your birth day, the last month isn’t counted as complete — that’s why you might see one month less than a simple division would suggest. This is the standard way age is expressed.

How is age calculated for someone born on February 29?

The calculator treats February 29 as a valid birth date. In non-leap years, the “anniversary” is considered to fall on February 28 for the purpose of month/day counting. The exact number of days lived is still accurate.

Can I calculate my age on a future date?

Yes. Change the “Calculate age as of” field to any future date, and the calculator will show how old you will be on that day.

Does the calculator account for time zones?

It uses the local date from your device. If you need age at a specific UTC time, results may vary by up to a day depending on your time zone.