Age Calculator
Calculate your exact age in years, months, days, hours, minutes, and seconds
Date of Birth
Age at the Date Of
Age Calculator — Frequently Asked Questions
How is exact age calculated?
Exact age is calculated by counting complete years, then remaining months, then remaining days between the birth date and the target date. The western age system counts age from your last birthday — so a person born January 15, 1990 turns 36 on January 15, 2026, and is 35 years old on January 14, 2026.
What is the difference between age in years and total days lived?
Age in years counts complete calendar years from birth. Total days lived counts every individual day — including the extra days in leap years. A 35-year-old has lived approximately 12,775–12,784 days depending on how many leap years fall in their lifetime.
How are leap years handled in age calculation?
Leap years (366 days) add one extra day to total days lived. The calculator accounts for this automatically using JavaScript's Date object, which correctly handles all historical and future leap years. This is why the "Total Days" and "Total Hours" figures are precise rather than approximate.
How does this age calculator find days until my next birthday?
The calculator finds the next occurrence of your birth month and day after today's date. If your birthday has already passed this year, it uses next year's date. The result is the number of days from today to that next birthday.
Quick Tips
- Calculates exact age between two dates
- Shows results in multiple units
- Counts days until your next birthday
- Based on the most common western age system