Calculate your exact age in years, months and days from your date of birth — plus total months, weeks, days, hours, minutes and seconds, the day you were born, and a next-birthday countdown. Leap-year accurate, with an optional age-difference comparison.
Last updated
Jul 2026
Reviewed by
EasyTechLabs Team
Calculation method
Documented in “How this is calculated” below
Official sources
ISO 8601 — date and time format, Gregorian calendar (leap-year rule)
Formula
Age = whole months between the dates (month-end clamped) → years & months, then residual days · Totals derive from the exact calendar day count (leap-aware)
Calculation method
Computes the exact calendar age from a date of birth to a chosen date (today by default). It finds the largest whole number of months between the two dates — clamping month ends, so 31 Jan + 1 month = 28/29 Feb — then the residual days to the target date. Total months, weeks, days, hours, minutes and seconds derive from the exact number of calendar days (UTC midnight difference), so leap days are counted precisely with no daylight-saving drift. The next birthday, the weekday of birth, and the optional two-date age difference use the same calendar arithmetic.
Assumptions
Limitations
Official sources & references