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
Age is the number of completed years since birth, but the exact years-months-days breakdown needs real calendar math. Months have 28 to 31 days, and February 29 birthdays need a rule for non-leap years. This calculator uses March 1 for leap-day birthdays in non-leap years. It also shows total days lived, days until your next birthday, and age on any 'As of' date for records, retirement planning, or milestone checks.
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.