Age Difference Calculator

Enter two birth dates to find the exact age gap between them.

Person A's birth date

Person B's birth date

Age difference

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What this calculator does

This age difference calculator finds the exact age gap between two people, expressed in years, months, and days, using the same calendar-accurate method as a standard age calculator. It also identifies which person is older.

Worked example

Person A was born on March 3, 1990 and Person B on November 20, 1992. The age gap between them is 2 years, 8 months, and 17 days, with Person A being older.

Common mistakes

Subtracting birth years only. Two people born in 1990 and 1992 aren't necessarily "2 years" apart in exact terms — the specific months and days matter.
Assuming the gap is fixed to whole years. The precise gap includes months and days, which matters for eligibility rules that specify an exact age difference.
Forgetting the gap can look like it "changes" year to year. Between the two people's birthdays, the described age gap in whole years can appear to shift by one.

Frequently asked questions

How do you calculate the age difference between two people?+

We find the calendar-accurate difference between the two birth dates, expressed as years, months, and days — the same method used for calculating a single person's exact age.

Does the order I enter the two birth dates matter?+

No — enter them in either order. The calculator automatically identifies which person is older and shows the gap accordingly.

Does the age gap change over time?+

The number of years between two birth dates never changes, but the described gap can appear to shift by a year around each person's birthday, since one person's "current age" advances before the other's does.

Is there a free online age gap calculator for relationships, siblings, or coworkers?+

Yes — this calculator works for any two birth dates, whatever the reason for comparing them.

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