An exact age difference is usually shown in three parts: years, months and days. These parts work together to show one complete gap.
Try the calculator with two dates of birth to see this result.
What the years mean
The year number shows how many full calendar years fit between the two dates.
If the older person was born on 10 May 1990 and the younger person was born on 10 May 1995, the gap is exactly 5 years.
What the months mean
After counting the full years, we count the full months that are left.
Months do not all have the same number of days. February is shorter than March. So, we count real calendar months instead of using 30 days for every month.
What the days mean
After counting full years and full months, a few days may still be left. These become the day part of the answer.
For example:
3 years, 2 months and 6 days
This means you move forward 3 full years, then 2 full months, then 6 days to reach the later date.
Exact gap and total days are different views
The answer in years, months and days is easy to understand. The total-day answer is useful when you need one number.
Both can be correct. They simply show the same gap in different ways.
A quick check
If the result says 12 months or more in the month part, something is wrong. Twelve full months should become one full year. The month part should normally stay between 0 and 11.
Use the Age Difference Calculator