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How to calculate age from a birthday in Excel and Google Sheets
Topic:Date arithmeticExcel & Google Sheets
=DATEDIF(A2,TODAY(),"Y")Try it with your data
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Step by step
- 1Enter the birth date in a cell, e.g., A2, formatted as a date.
- 2In an adjacent cell, enter =DATEDIF(A2,TODAY(),"Y").
- 3DATEDIF calculates the complete years between the birth date and today.
- 4For a more detailed result such as '32 years, 4 months', extend to: =DATEDIF(A2,TODAY(),"Y")&" yrs "&DATEDIF(A2,TODAY(),"YM")&" mo".
- 5Press Enter. The cell displays the person's age in whole years.
Tips
- DATEDIF is an undocumented legacy function in Excel but works reliably. In Google Sheets it is fully supported. Always supply start_date before end_date or you will get a #NUM! error.
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Frequently asked
Why does my age show as a date serial number?
The result cell is formatted as a date. Change the cell format to Number or General: right-click the cell, choose Format Cells, and select Number.
Can I calculate age at a specific past or future date instead of today?
Replace TODAY() with any date: =DATEDIF(A2,"2030-01-01","Y") calculates the age on January 1, 2030.
More on Date arithmetic
See all →Reference
TODAY / DATEDIF
Work with the current date and measure the gap between two dates.
How-toHow to calculate age from a date of birth
Turn a birth date into an age in years with DATEDIF and TODAY. Works the same in Excel and Google Sheets.
ReferenceDATEDIF
Calculates the difference between two dates in years, months, or days using a unit code string.
How-toHow to calculate days between two dates
Subtract one date from another to get the number of days, or count working days with NETWORKDAYS. Works in both apps.
How-toHow to add months to a date
Shift a date forward or back by a number of months with EDATE — it handles month lengths correctly. Works in both apps.
How-toHow to flag overdue dates
Mark rows whose due date has passed by comparing it to TODAY() with IF. Works the same in Excel and Google Sheets.