UTILITIES · FREE TOOL
Age calculator
Calculate calendar age and elapsed days with an explicit leap-day convention.
Your inputs
Enter your values, then calculate.
Decimal-point numbers; displayed rounding does not change internal values. Calculations stay on this device.
YOUR RESULT
Make the numbers clear.
Save calculation JSON ↓Calculation breakdown
Scroll sideways to see every column. You can also focus the table and use the arrow keys.
How this calculation works
Compare calendar anniversaries, then count residual months and days. A Feb29 anniversary clamps to Feb28 in a non-leap year. This is a calendar convention, not a jurisdiction-specific legal age determination. Dates are Gregorian calendar days, without time zones.
Check the assumptions
Use the stated units and conventions. This tool supports the workflow described here; it does not infer missing information or outside rules.