Age Calculator
Calculate your exact age in years, months, and days, and find out how many days until your next birthday.
How It Works
- 1
Enter your date of birth
Select your birth date. The 'As of' date defaults to today but can be changed.
- 2
View your exact age
See years, months, days, total days lived, and days until your next birthday.
- 3
Explore different dates
Change the 'As of' date to see your age at any past or future point.
How Age Is Calculated
While asking someone's age seems like the simplest question, the precise calculation involves subtle complexities. Age is expressed as the number of completed years since birth. But the breakdown into years, months, and days requires careful calendar arithmetic: months vary from 28 to 31 days, and leap year birthdays (February 29) present a unique challenge. Our calculator uses the standard convention: if born on February 29, your birthday in non-leap years is counted as March 1. Beyond the basic age, the calculator shows total days lived — a 30-year-old has lived roughly 10,950 days — and counts down to your next birthday. The 'As of' date feature lets you calculate age at any point in time, useful for genealogy, retirement planning, and life milestones.
Frequently Asked Questions
How is age calculated?
Age is calculated by finding the difference between your date of birth and today's date (or any reference date). The result is expressed in years, months, and days. A full year is completed on each birthday.
How does this calculator handle leap year birthdays?
If you were born on February 29 in a leap year, your birthday is treated as February 28 in non-leap years for the purpose of counting completed years.
Can I calculate age at a specific past or future date?
Yes — use the 'As of' date field to choose any reference date. This lets you calculate how old you were at a specific point in the past, or how old you will be on a future date.