Birth Calculator
Calculate your age, next birthday, and days until your next birthday based on your date of birth.
Published by:
isCalculator Editorial Team
Reviewed by:
Review Board
Last Updated:
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How to use this tool?
How to use the Birth Calculator:
- Enter your Date of Birth – Use the date picker (format: YYYY-MM-DD). This is required.
- Optional: Enter a Target Date – If left blank, today’s date is used. The calculator will compute your age as of this date.
- Click "Calculate" – The results appear below.
What you get:
- Age – Your age in full years on the target date.
- Next Birthday – The date of your next birthday after the target date.
- Days Until Next Birthday – The number of days from the target date to that next birthday.
Notes:
- All dates are in the Gregorian calendar. No time zones are considered – only dates matter.
- If your birth date is after the target date, an error will appear.
- The calculation adjusts for whether your birthday has already occurred in the target year.
Previous Results
| Result | Inputs | Date |
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Frequently Asked Questions
Age is calculated by subtracting the birth year from the target year, then adjusting if the birthday hasn't occurred yet in the target year.
If no target date is entered, today's date is used as the target date.
Yes, you can enter any target date. The calculator will compute your age on that date and the next birthday after it.