Age Calculator
Calculate age from date of birth to today or any date
What is an age calculator?
An age calculator computes the exact time elapsed between a date of birth and another date — typically today. The result is expressed in years, months, and days because calendar months and years have different lengths, making simple subtraction in days insufficient for precise age.
Our calculator also shows your age in total days, weeks, and hours — giving you a fuller picture of time lived.
How age is calculated
Calculating age isn't as simple as subtracting two dates. Here's how it works properly:
Compare years
Subtract the birth year from the target year to get a base year count.
Adjust for months
If the current month is before the birth month, subtract one from the year count. The remaining difference gives whole months.
Handle days
If the current day is before the birth day, borrow days from the previous month and adjust accordingly. The result is the remaining days.
Leap years
Leap years (Feb 29 birthdays) are handled by advancing the birthday to March 1 in non-leap years.
Examples
| Date of birth | Today | Age |
|---|---|---|
| January 1, 1990 | January 1, 2025 | 35 years, 0 months, 0 days |
| March 15, 2000 | July 10, 2025 | 25 years, 3 months, 25 days |
| December 31, 1985 | January 1, 2025 | 39 years, 0 months, 1 day |
| February 29, 2000 | February 28, 2025 | 24 years, 11 months, 30 days |
Frequently asked questions
Enter your date of birth and today's date in the calculator above. It will compute your exact age in years, months, and remaining days, accounting for leap years and varying month lengths.
If you were born on February 29 (a leap day), your birthday falls on February 28 in non-leap years in most countries (some use March 1). Our calculator uses February 28 for non-leap years.
Yes — just enter the person's date of birth. You can also change the "Age on date" field to calculate how old they were on a specific date in the past or future.
Enter your birth date and the calculator will show your total days lived alongside your years, months, and days result. The average person lives around 27,000–29,000 days.
This calculator uses the Gregorian calendar, which is the international standard. It correctly handles all time zones by using only the date (not time), so there is no timezone ambiguity.