Date & Age Calculator — exact age and days between dates

This tool has two modes. Enter a date of birth to get your exact age in years, months and days, or pick two dates to count the days and weeks between them.

How the count works

Age is measured from your birth date to today, adjusting for months of different lengths and leap years. The days-between mode counts calendar days from one date to another, ignoring the time of day.

Common uses

Work out an exact age for forms, count down to a deadline or event, find how many days you have lived, or measure a project’s length. Everything updates instantly as you change the dates.

Why leap years matter

A leap year adds February 29th every four years (with a small correction for century years) to keep the calendar aligned with the seasons. The calculator accounts for this automatically, so counts that cross a leap day stay correct.

Handy for planning

Use the days-between mode to count down to a wedding, holiday or launch, to measure a notice period, or to check how old a document is. Because it counts calendar days, weekends and holidays are included.

Example

From 1 January to 31 December in a normal year there are 364 days between the two dates; in a leap year there are 365.

How the dates are counted

Dates are handled as calendar days, ignoring the time of day. Age is measured from your birth date to today, borrowing days from the previous month and a year when needed, so months of different lengths come out right. Leap years follow the Gregorian rule — a February 29th every four years, skipping century years not divisible by 400 — and the tool applies this automatically.

The between-dates mode is handy for counting down to a holiday, deadline or birthday, and it includes weekends and public holidays in the total.

Built, tested and maintained by the Everyday Calculators team. How we calculate →