EVERYDAY MATH
Age Calculator
Find the age between a birthday and any date you choose.
Your dates
Choose a birth date and a target date on or after it.
THE BIG PICTURE
Your age summary
Your numbers, with a clearer view.
Enter both dates and calculate to see the age in years, months, and days.
Month-end birthdays use the last available day in shorter months. This is a calendar calculation.
Enter both dates and calculate to see the age in years, months, and days.How the age calculator counts dates
Choose a birth date and a target date on or after it. The calculator counts completed calendar years and months, then the remaining days. You can use a past or future target date.
Formula
Age = completed years + remaining calendar months + remaining days
Example
From January 31, 2025 to March 1, 2025, the result is 0 years, 1 month, and 1 day. The monthly anniversary falls on February 28 in that shorter month.
Assumptions and limits
Month-end anniversaries use the last available day in shorter months. February 29 anniversaries fall on February 28 in non-leap years. This is a calendar calculation, not a determination of legal age.