Guide
How to Calculate the Number of Days Between Dates
Learn how elapsed calendar days are counted between two selected dates.
Key idea
Learn how elapsed calendar days are counted between two selected dates.
Formula or method
The day difference is the elapsed number of calendar midnights between dates.
Worked example
Start with the values in your question, substitute them into the formula, and keep the units consistent. For example, if a rate is given as 15%, use 0.15 when a formula requires a decimal.
Common mistakes
- Mixing percentage points with percentage change.
- Using different units for the same calculation.
- Rounding too early when several steps are involved.
Tip: Use the matching AvyTool calculator to check your result after working through the method.
Why the result can differ
Real-world calculations can include assumptions, rounding, fees, tax rules, calendar conventions, or other details. Treat simple calculator results as estimates when the underlying situation is more complex.