To find how many days apart two people are, compare their full dates of birth.
The Age Difference Calculator shows the total number of days along with years, months and days.
Use the full dates
You need the day, month and year for both people. Birth years alone cannot give the correct number of days.
For example, two people born in different years may be only one day apart. Two people born in the same year may be hundreds of days apart.
Example
Compare 1 March 2000 and 11 March 2000.
Ten full days passed between the two dates. So, the two people are 10 days apart.
Leap days are counted
If 29 February falls between the dates, it is included in the total. You do not need to add it yourself.
“Days apart” and “dates counted” are different
From 1 March to 2 March, one day has passed. So the dates are one day apart.
If you count both calendar dates, you see two dates: 1 March and 2 March. This is a different type of counting.
The calculator shows elapsed days, or days apart.
Annual birthdays are another question
The number of days between two birthday celebrations can change from year to year because of leap years.
The fixed total-day age gap compares the original dates of birth. It does not count the distance between birthday celebrations every year.
Protect the dates
Birth dates are personal information. Share the total gap instead of sharing names with full dates whenever possible.
Use the Age Difference Calculator