Age Calculator
Exact age in years, months, days, and total units.
Defaults to today. Change it to work out your age on any date.
Age
—
How the Age Calculator works
Calculates age the way people actually count it — full years, then remaining months, then remaining days — while handling leap years and uneven month lengths correctly. It also shows the totals in each unit and how long until your next birthday.
Frequently asked questions
How is age calculated exactly?
By counting completed years from the birth date, then completed months from that anniversary, then remaining days. This is why the day count varies: the same gap can be '1 month 2 days' or '1 month 3 days' depending on whether the month it crosses has 30 or 31 days.
How are leap years handled?
The calculation works on actual calendar dates, so leap days are included automatically in day totals. For someone born on 29 February, the birthday is treated as 1 March in non-leap years, which is the common legal convention.
Why does my age in months not match years × 12?
Because months have different lengths. 'Total months' counts completed calendar months, while years × 12 assumes uniform months. The two agree only exactly on your birthday.
What is chronological age used for?
Eligibility thresholds mostly — school entry, driving, voting, retirement benefits, and medication dosing. Most of these use completed years on a specific cut-off date, which is why the exact day matters.