Age Calculator

Pick a date of birth and this works out an exact age in years, months and days — not just years — along with totals in weeks, days and hours, and a countdown to the next birthday.

Why 'exact age' is more than one number

Age in whole years hides how far someone is through the current year. Two people who are both '34' can be a full year apart in actual age. The years/months/days breakdown here is calendar-accurate — it accounts for the actual number of days in each month and leap years, rather than assuming every month is 30 days, which is the shortcut simpler calculators take and which drifts increasingly wrong the further the birth date is from today.

Total days, weeks and hours

Seeing age as a single large number — total days lived, or total hours — is a common way to mark a milestone (10,000 days old, for instance, falls at just under 27 years and 4 months). These totals are simple counts from date of birth to today, useful for birthday-adjacent milestones that don't fall on a round number of years.

Next birthday countdown

This counts forward from today to the next occurrence of the birth month and day, wrapping to next year automatically once the birthday has passed this year.