Age Difference Calculator
Figure out the age gap between two people using the age difference calculator below.
Age Difference:
| Difference in Years: | |
| Difference in Months: | |
| Difference in Days: |
| Difference in Years: | |
| Difference in Months: | |
| Difference in Days: |
| Difference in Years: | |
| Difference in Months: | |
| Difference in Days: |
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Joe is the creator of Inch Calculator and has over 20 years of experience in engineering and construction. He holds several degrees and certifications.
How to Calculate an Age Difference
You can calculate an age gap between two people using the same method as calculating any other date range. There are a few steps to follow to calculate an age difference:
Step One: Break Down the Birth Dates
A birthdate consists of three parts:
- Day: The day of the month (1 to 31)
- Month: The month of the year (1 to 12)
- Year: The calendar year
Step Two: Calculate the Age Gap in Years
When the birthdates fall on the same month and day, then you can calculate the age difference by subtracting the birth years.
When the birthdates fall on a different day or month, then you need to calculate the age gap in days and months to get a precise difference.
Subtracting the year of the earlier birthdate from the year in the later one will give you the age difference in years, but this may need to be adjusted in the next step to account for a partial year.
Step Three: Calculate the Age Gap in Months
Next, you’ll need to calculate the remaining age difference in months. Do this by determining if the month in the earlier birthdate is before or after the month in the later one.
If the month in the later birthdate is later in the year than the month in the earlier one, then you can subtract the month number in the earlier birthdate from the month in the later one.
However, if the month in the later date is earlier in the year than the month in the first birthdate, then the process is slightly different.
In this case, you’ll need to add 12 to the month number in the later birthdate before subtracting. Then, you’ll need to subtract 1 from the difference in years you found in step two to account for the additional 12 months.
You can use our years between dates calculator to validate the age gap in years.
Step Four: Calculate the Age Gap in Days
The final step is to figure out the remaining age difference in days. Just like in the previous step, you need to start by determining if the day in the earlier birthdate is before or after the day in the other one.
If the day in the later birthdate is bigger than the day in the first birthdate, then you can subtract the day in the first date from the day in the second one.
But, if the day in the later birthdate is smaller than the day in the start date, then you need to count the days from the date in the month to the day of the following month to find the number of days in between.
In this case, to account for the extra days added, subtract 1 from the months you found in the previous step.
You can also use our days since calculator to find how many days there are since your birthdate.