Excel Formula Basics
Excel Formula Basics introduces how formulas are written, the order in which Excel calculates them, and common beginner mistakes to avoid.
What Is a Formula?
A formula is an instruction you type into a cell so that Excel calculates a result instead of just displaying text. Every formula must start with an equals sign (=). Without that leading =, Excel treats whatever you type as plain text or a number, not as something to calculate.
Example
=5+3Basic Arithmetic Operators
Order of Operations
Excel calculates a formula using the same order of operations as standard math: anything inside parentheses is calculated first, then exponents, then multiplication and division (worked left to right), and finally addition and subtraction (also worked left to right). Operators of equal rank, like * and /, are simply evaluated in the order they appear.
Example
=2+3*4Referencing Cells in Formulas
Instead of typing raw numbers into a formula, point to the cells that hold those numbers, such as =A1+A2. This way, if the value in A1 or A2 changes later, the formula automatically recalculates, which is the whole reason spreadsheets are so useful for anything that might change.
- Typing a formula without the leading = sign, so Excel stores it as plain text
- Mismatched or missing parentheses, which change the calculated result
- Referencing the wrong cell, especially after inserting or deleting rows
- Mixing text and numbers in a way a formula cannot calculate, such as =A1+"total"
