The age difference between a parent and child is the gap between their dates of birth.
Enter both dates in the Age Difference Calculator. The parent’s date will normally be earlier, so the calculator will show the parent as older.
Use both full dates
Do not subtract only the birth years. The month and day also matter.
Example:
- Parent: 20 December 1985
- Child: 5 January 2015
Subtracting the years gives 30. But the exact gap is less than 30 years because the child’s January birthday comes before the parent’s December birthday in the calendar.
Why current ages are not enough
A parent and child may say they are 40 and 10. That sounds like a 30-year gap. But whole-number ages leave out months and days.
The birth dates give the fixed and correct gap.
Parent’s age when the child was born
The parent-child age gap is also the parent’s age on the child’s date of birth.
For example, if the gap is 29 years and 16 days, the parent was 29 years and 16 days old when the child was born.
Old family records
Sometimes only a birth year is known. In that case, you can find only a rough gap. Do not present it as an exact answer.
Keep the context clear
This calculator compares dates only. It does not prove a family relationship. Also, keep full birth dates private when sharing family information online.
Use the Age Difference Calculator