Free Online Calculators for Age, Dates, BMI & Percentages

How the age calculator works

This age calculator compares your date of birth with today's date and displays the completed years, remaining months and remaining days. It accounts for different month lengths and leap years. Your result updates when you run the calculation, so check the date you entered if the answer looks unexpected.

How to calculate your age

1. Choose your birth day, month and year.
2. Select Calculate Age.
3. Read your age in years, months and days in the result panel.

The calculator performs the calculation in your browser. Do not use a general age result as an official proof of age; legal definitions and cut-off dates can vary by country, organisation and purpose.

Why can age in days differ from age in years?

A calendar year is not always exactly 365 days because leap years add an extra day. Months also have different lengths. For this reason, a calendar-based age breakdown is different from simply dividing the number of days lived by 365.

Other things to know

Age can be expressed in several ways: calendar years, calendar months, or total elapsed days. Each method answers a slightly different question. Use the dedicated calculator above and review its notes for the exact counting method.