How to Put Formula in Excel to Calculate Age
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Reviewed by Calculator Editorial Team
Calculating age in Excel is a common task for spreadsheets that track birth dates, membership ages, or other time-based data. This guide explains how to use Excel formulas to calculate age accurately, including exact age with months and days, age from year only, and age in different units.
Basic Formula to Calculate Age
The simplest way to calculate age in Excel is to subtract the birth year from the current year. This gives you the person's age in whole years.
Formula: =YEAR(TODAY()) - B2
Where B2 contains the birth year (e.g., 1990).
This formula works well for basic age calculations but doesn't account for whether the birthday has already occurred in the current year. For more precise calculations, you'll need to use more complex formulas.
Calculating Exact Age (Including Months and Days)
To calculate exact age including months and days, you can use the following formula:
Formula: =DATEDIF(B2, TODAY(), "Y") & " years, " & DATEDIF(B2, TODAY(), "YM") & " months, " & DATEDIF(B2, TODAY(), "MD") & " days"
Where B2 contains the birth date (e.g., 1/15/1990).
This formula uses the DATEDIF function to calculate the difference between the birth date and today's date in years, months, and days. The result will look like "33 years, 5 months, 12 days".
Note: The DATEDIF function is available in Excel 2010 and later. For older versions, you'll need to use a more complex formula involving YEAR, MONTH, and DAY functions.
Calculating Age from Year Only
If you only have the birth year and want to calculate age, you can use this simple formula:
Formula: =YEAR(TODAY()) - B2
Where B2 contains the birth year (e.g., 1990).
This formula gives you the person's age in whole years. It's useful when you don't have the exact birth date but only the year.
Calculating Age in Months
To calculate age in months, you can use the following formula:
Formula: =DATEDIF(B2, TODAY(), "M")
Where B2 contains the birth date (e.g., 1/15/1990).
This formula uses the DATEDIF function to calculate the difference between the birth date and today's date in months.
Calculating Age in Days
To calculate age in days, you can use the following formula:
Formula: =DATEDIF(B2, TODAY(), "D")
Where B2 contains the birth date (e.g., 1/15/1990).
This formula uses the DATEDIF function to calculate the difference between the birth date and today's date in days.
Calculating Age in Years, Months, and Days
For a more detailed breakdown of age, you can use this formula:
Formula: =DATEDIF(B2, TODAY(), "Y") & " years, " & DATEDIF(B2, TODAY(), "YM") & " months, " & DATEDIF(B2, TODAY(), "MD") & " days"
Where B2 contains the birth date (e.g., 1/15/1990).
This formula combines the DATEDIF function with text concatenation to display age in years, months, and days.
Using Excel's DAYS360 Function
The DAYS360 function calculates the number of days between two dates based on a 30-day month system, which is often used in financial calculations.
Formula: =DAYS360(B2, TODAY())
Where B2 contains the birth date (e.g., 1/15/1990).
This formula calculates the number of days between the birth date and today's date using the 30-day month system.
Calculating Age in Google Sheets
Google Sheets has similar functions for calculating age. The basic formula is:
Formula: =YEAR(TODAY()) - YEAR(B2)
Where B2 contains the birth date (e.g., 1/15/1990).
For more precise calculations, you can use the DATEDIF function in Google Sheets:
Formula: =DATEDIF(B2, TODAY(), "Y") & " years, " & DATEDIF(B2, TODAY(), "YM") & " months, " & DATEDIF(B2, TODAY(), "MD") & " days"
Where B2 contains the birth date (e.g., 1/15/1990).
Common Mistakes to Avoid
1. Not Accounting for the Current Date
When calculating age, it's important to use the current date (TODAY()) rather than a fixed date. This ensures the calculation updates automatically as time passes.
2. Using Incorrect Date Formats
Excel and Google Sheets can be particular about date formats. Make sure your birth dates are formatted as dates (not text) to avoid calculation errors.
3. Forgetting to Update Formulas
If you're using a fixed date in your formula, remember to update it periodically to keep the calculations accurate.
Frequently Asked Questions
Can I calculate age in Excel without using the DATEDIF function?
Yes, you can use a combination of YEAR, MONTH, and DAY functions to calculate age without DATEDIF. However, this requires more complex formulas and may not be as accurate.
How do I calculate age in Excel if the birth date is in a different format?
Make sure the birth date is formatted as a date in Excel. You can use the DATEVALUE function to convert text dates to proper date formats if needed.
Can I calculate age in Excel for multiple people at once?
Yes, you can apply the same formula to multiple cells by dragging the fill handle or using array formulas. This allows you to calculate age for an entire column of birth dates.
How do I calculate age in Excel if the birth date is in a different time zone?
Excel doesn't automatically account for time zones when calculating dates. You'll need to adjust the birth date manually to match the time zone you're working in.