Age Calculator
Calculate exact age in years, months, days, hours and minutes from any date of birth.
TL;DR — Age Calculator: An age calculator computes the precise duration between a date of birth and a reference date (defaults to today). Cal44 expresses the result in multiple units — years and months and days, total days, total weeks, total hours — and shows the number of days until the next birthday.
What is the Age Calculator?
An age calculator computes the precise duration between a date of birth and a reference date (defaults to today). Cal44 expresses the result in multiple units — years and months and days, total days, total weeks, total hours — and shows the number of days until the next birthday.
How to use the Age Calculator
- Enter the date of birth.
- Optionally change the reference date (defaults to today).
- Read the exact age in years, months and days, plus aggregated totals and the countdown to the next birthday.
Formula
Years = floor((Now − DOB) in years) Then subtract years; convert remainder to months; subtract months; remainder is days.
Total days = (Now − DOB) ÷ 86,400,000 ms. Months in the year-month-day decomposition account for variable month lengths.
Worked example
Born 1990-04-12, today 2026-05-24. Age = 36 years, 1 month, 12 days. Total days ≈ 13,191. Next birthday in 323 days.
Frequently asked questions
How is age calculated exactly?
By computing the difference between two dates and decomposing into completed years, then completed months, then remaining days, accounting for different month lengths and leap years.
Does the age calculator account for leap years?
Yes. February 29 birthdays in non-leap years are conventionally observed on March 1 for legal purposes; the calculator shows true elapsed time regardless.
Can I calculate age between two non-today dates?
Yes — set the "as of" date to whatever date you want. Useful for calculating age at a past event (e.g. age on a wedding date).
How accurate are the hours and minutes?
Hours and minutes are based on midnight-to-now elapsed time from the date of birth, not the exact time of birth.
How can I find someone's zodiac sign?
Cal44 doesn't compute astrological signs, but the date of birth you enter determines it: e.g. Apr 20 – May 20 is Taurus.