Formula guide · Excel and Google Sheets · Updated May 13, 2026
Calculate Age from Date of Birth
Calculate age in years from a birth date using DATEDIF in Excel or Google Sheets.
Quick Answer
Use DATEDIF with TODAY and the Y unit to calculate complete years of age.
Copyable Formula
=DATEDIF(A2,TODAY(),"Y")Syntax
=DATEDIF(birth_date,TODAY(),"Y")Excel and Google Sheets
Worked Example
| A | B |
|---|---|
| Date of birth | Age |
| 1990-04-15 | 36 |
Result: Returns complete years between the birth date and today.
Steps
- Store the birth date as a real date value.
- Use TODAY as the end date.
- Use the Y unit for complete years.
- Format the result as a number, not a date.
Common Mistakes
- Subtracting dates and dividing by 365 without handling birthdays correctly.
- Using text dates that the spreadsheet does not recognize.
- Formatting the age result as a date by accident.
Excel vs Google Sheets Notes
The core idea works in both Excel and Google Sheets, but separators, function availability, and array behavior can vary by account, locale, and version.
Editorial check: This guide was last updated May 13, 2026. Formula behavior can vary by Excel version, Google Sheets rollout, and spreadsheet locale.