You need to perform calculations in Excel but are unsure how to write the formulas. Excel formulas use standard arithmetic operators for basic math. This article explains how to use the plus, minus, multiply, and divide signs to create formulas for addition, subtraction, multiplication, and division.
Key Takeaways: Basic Math Operators in Excel
- Plus sign (+): Adds the values of two or more cells or numbers together.
- Minus sign (-): Subtracts one value from another to find the difference.
- Asterisk (*): Multiplies numbers or cell values together.
- Forward slash (/): Divides the first number by the second number.
Understanding Excel’s Formula Syntax and Operators
All Excel formulas begin with an equals sign (=). This tells Excel that the content of the cell is a calculation, not plain text. After the equals sign, you build the formula using cell references, numbers, and arithmetic operators. The basic operators are the plus sign for addition, the minus sign for subtraction, the asterisk for multiplication, and the forward slash for division.
You can use these operators directly with numbers, like =5+3. For practical use, you reference cells containing your data, like =A1+B1. When you use cell references, Excel automatically updates the result if you change the numbers in those cells. This dynamic calculation is a core strength of Excel.
Order of Operations
Excel follows the standard mathematical order of operations, often remembered by the acronym PEMDAS. Calculations inside parentheses are done first, followed by exponents. Multiplication and division are performed next, from left to right. Addition and subtraction are performed last, also from left to right. For example, in the formula =10+5*2, Excel multiplies 5 by 2 first, then adds 10, resulting in 20. To force addition first, use parentheses: =(10+5)*2, which results in 30.
Steps to Create Basic Math Formulas
Follow these steps to write formulas using the four basic arithmetic operators. Always start by typing the equals sign in the cell where you want the answer to appear.
- Start the formula
Click on the cell where you want the calculation result. Type the equals sign (=). This is required for every formula. - Add numbers or cell references
Type the first number or click on the first cell you want to use in the calculation. For example, click on cell A1. You will see its cell reference appear after the equals sign. - Type the arithmetic operator
Type the operator for your calculation: the plus sign (+), minus sign (-), asterisk (*), or forward slash (/). - Add the second number or reference
Type the second number or click on the second cell, like B1. Your formula bar should now show something like =A1+B1. - Complete the formula
Press the Enter key. Excel will calculate the result and display it in the cell. The formula itself remains visible in the formula bar above the grid when the cell is selected.
Method for Using Constant Numbers
You can also write formulas using constant numbers without cell references. This is useful for quick, one-time calculations. The process is the same but you type the numbers directly.
- Select the result cell and type =
Click any cell and type the equals sign to begin. - Type the full calculation
Immediately type the numbers and operators, such as =150-25 or =12*4.5. - Press Enter
Excel calculates and displays the result. The formula is replaced by the static answer unless you edit the cell again.
Common Mistakes and Things to Avoid
Forgetting the Equals Sign
If you type A1+B1 without an equals sign, Excel treats it as text. The cell will display “A1+B1” instead of performing the calculation. Always start with = to activate formula mode.
Using the Wrong Symbol for Multiplication
The multiplication operator is the asterisk (*), not the letter X or a dot. Typing =A1 x B1 or =A1.B1 will cause a #NAME? error. Always use the asterisk key for multiplication.
Dividing by Zero or an Empty Cell
Division by zero is mathematically undefined. If your formula divides by a cell that is empty or contains zero, like =A1/B1 where B1 is zero, Excel will display a #DIV/0! error. Check your divisor cell to ensure it contains a number other than zero.
Ignoring Cell Formatting
If your result cell is formatted as Text, your formula will not calculate. It will display as plain text. To fix this, select the cell, go to Home > Number format dropdown, and choose General or Number. Then re-enter the formula by clicking in the formula bar and pressing Enter.
Basic Arithmetic Operators: A Comparison
| Item | Addition (+) | Subtraction (-) | Multiplication (*) | Division (/) |
|---|---|---|---|---|
| Operator Symbol | Plus sign | Minus sign | Asterisk | Forward slash |
| Example Formula | =A2+B2 | =A2-B2 | =A2*B2 | =A2/B2 |
| Primary Use | Summing values | Finding the difference | Calculating product or total | Calculating ratio or unit value |
| Common Error | None specific | None specific | Using ‘x’ instead of * | #DIV/0! from dividing by zero |
| Order of Operations | Calculated after * and / | Calculated after * and / | Calculated before + and – | Calculated before + and – |
You can now create formulas in Excel for addition, subtraction, multiplication, and division. Remember to always start with an equals sign and use the correct operator symbols. For your next calculation, try using the SUM function by typing =SUM( and selecting a range of cells. To quickly edit any formula, double-click the cell containing it or press F2 while the cell is selected.