Excel Function Reference

Here you find my working reference for Excel functions, the everyday formulas that turn a plain spreadsheet into something that calculates, summarizes, and reports for you. I do not want to duplicate Microsoft's documentation. I want to explore each function in depth so you understand not just what it does, but how it behaves once you put it to work on real data. I am building this reference one function at a time, and each entry goes deep. Take the "Count" function: on the surface it just counts, but I show you exactly which cells it counts and which it quietly ignores, so you are never surprised by a total that looks too low. The "Sum" function gets the same treatment, from adding a range to the ways it handles text, blanks, and errors that can throw your results off.