Age Calculator

What Is an Age Calculator?

An age calculator determines how much time has elapsed between a person's date of birth and a selected calculation date. Instead of simply subtracting one year from another, an exact age calculation considers the day and month as well as the year.

This free online age calculator can calculate your chronological age in completed years, months and days. You can use today's date or choose a different date to determine how old you were or will be on a particular day.

Why Use the Age Calculator?

Calculating an exact age manually can be inconvenient because months have different numbers of days and leap years affect the total elapsed time. This calculator performs the calendar calculation automatically.

How to Use the Age Calculator

Enter your date of birth and select the date on which you want to calculate your age. For your current age, use today's date.

1. Enter your date of birth — Select your day, month and year of birth in the Date of birth field.
2. Choose a calculation date — Leave today's date selected to calculate your current age, or select another valid date.
3. Calculate your age — Select Calculate Age to perform the calculation.
4. Review the results — The calculator displays your exact age, total elapsed time and next birthday.

How Is Age Calculated?

Age is normally expressed as the number of complete years that have passed since a person's date of birth. An exact chronological age can also be expressed using the remaining months and days after those completed years have been counted.

For example, someone born on 15 March 1990 would reach 36 years of age on 15 March 2026. On 3 September 2026, that person would be 36 years, 5 months and 19 days old. The calculator performs this calendar-based calculation automatically.

Calculating Age in Years, Months and Days

The calculator first determines the number of completed years between the birth date and the calculation date. It then calculates the remaining complete months and days. This approach reflects how chronological age is normally stated and avoids treating every year or month as having a fixed number of days.

Why Birthdays Matter When Calculating Age

A person's age in completed years changes on their birthday, not simply when the calendar year changes. Someone born late in a year may therefore have a different completed age from another person born earlier in the same year, even when both birth years are identical.

Age Calculator Accuracy and Limitations

The calculator uses the dates entered by the user and calculates the elapsed calendar period between them. It does not require a name, account or other personal information. Results depend on the accuracy of the date of birth entered.

The calculation date can be in the past, present or future, but it cannot be earlier than the date of birth. Dates are interpreted according to the calendar date entered rather than a particular time of day or time zone.

Frequently Asked Questions