Age Calculator
Calculate exact age and the next birthday.
Input
This tool runs entirely in your browser. The data you paste or load is never uploaded.
Result
Enter your input, then run the tool.
About this tool
Calculates age in years, months and days from a birth date, plus total days lived and the weekday of the next birthday. Handles leap-day birthdays without silently shifting the date.
How to use it
- Enter the date of birth.
- Optionally change the “as of” date.
- Read the exact age and upcoming birthday.
Frequently asked questions
How is a 29 February birthday handled?
In non-leap years the birthday is treated as 1 March for age purposes, which matches common legal practice.
Does it use local time?
Dates are treated as calendar dates without time zones, which avoids off-by-one errors.
Keep going
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