AtlasCalc📅 TimebeginnerOffline
Age Calculator
Calculate exact age in years, months, and days from a birthdate.
Inputs
Enter your values below.
Result
Your answer appears here.
Enter values and press Calculate — the result appears here.
How it works
The formula behind this calculator.
age = asOfDate − birthDate
- birthDate
- Date of birth
- asOfDate
- The date to compute age at
Subtracting two dates gives the elapsed time. The result is exact down to days, accounting for leap years.
Example: Born 1990-06-15, today 2025-01-01 → 34 years, 6 months, 17 days
Ref: Gregorian calendar
Tips
- 💡 Age in days/weeks is fun for birthdays. To 1 year old = ~365 days, 10 = ~3,650.
- 💡 Leap years add an extra day every 4 years (except centuries not divisible by 400).