How to use the exact age calculator
Enter a birth date and choose an optional comparison date. The result uses completed calendar years and months rather than dividing by an average year length.
How the calculation works
Age is counted from day zero at birth. Leap days and the varying lengths of months are included. For someone born on the 31st, monthly anniversaries are clamped to the final day of a shorter month.
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 calculate my age on a past date?
Yes. Change the “Age as of” date to any date on or after your date of birth.
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.