How to use the birth year calculator
Enter a person’s age, the month and day of their birthday, and the date the age applies to.
How the calculation works
Age alone can imply two birth years depending on whether the birthday has passed. Including the birthday month and day removes that uncertainty.
Check your inputs carefully: an incorrect date can change a result. Dates and times are entered using your device settings, and no account is needed. For formal, legal, medical or financial purposes, verify the applicable local rules and official records.
Frequently asked questions
Can I use only an age?
You need the birthday month and day as well to determine one specific birth year.
Does the calculator account for leap years?
Yes. AgeGlide uses calendar-based calculations and includes 29 February where applicable.
Are the dates I enter uploaded?
No. AgeGlide calculates your results in your browser. Entered dates are not sent to our server for processing.