CalculatorsLocal (offline)
Age Calculator
Enter a date of birth and, optionally, the date to measure to (today by default). The result shows age in completed years, months and days, total days and weeks, and days until the next birthday. 29 February birthdays fall on 28 February in common years.
This tool runs in an isolated frame on tools.freetoolspro.com. Your files and inputs stay on your device, and advertising on this page cannot read them.
Method
Calendar arithmetic in UTC: whole years, then whole months, then remaining days, borrowing the length of the previous month when needed.
Privacy
Dates stay in your browser frame and are not stored or sent anywhere.
Common questions
Does it account for leap years?
Yes, using real calendar month lengths.
Can I calculate age at a past date?
Yes, set the “Age on” date.
Methodology reviewed 2026-10-27. Processing details and test approach.