Guide1 min readUpdated July 8, 2026
How to calculate your exact age
Short answer
Subtract the birth date from today: count the whole years first, then the remaining months, then the leftover days. A calculator handles leap years and month lengths automatically so the day count is exact.
The method
Age is the elapsed time between a birth date and today. The reliable way to get years, months, and days is to subtract each component in order and borrow when a value goes negative — exactly how you subtract mixed units.
- YearsSubtract the birth year from the current year.
- MonthsSubtract the birth month; if negative, borrow 12 months from the years.
- DaysSubtract the birth day; if negative, borrow days from the previous month.
Try it: Age CalculatorEnter your birth date for an exact age in years, months, and days.Open tool
Leap years and month lengthsBecause months have 28-31 days and leap years add a 29th of February, counting days by hand is error-prone. A calculator uses the real calendar, so the day count is exact.
Age between any two dates
The same method finds the gap between any two dates, not just birthdays — useful for anniversaries, project durations, or 'days until' countdowns. See time zones if the two dates span regions.