Formulas are equations that perform calculations on values in your sheet. All formulas begin with an equal sign (=). You can create a simple formula by using numbers and operators. For example, the formula =5+2*3, multiplies two numbers and then adds a number to the result.
You can use cell values in formulas, for example, =A1+A2 adds the values in cell A1 and cell A2. If you are working with long columns of data, you can use a range in the formula. For example, A1:A100 represents the first hundred numbers in column A. When you change the data in a cell referenced in a formula, Excel recalculates the results automatically.
You can also create a formula by using a function, a predefined formula that simplifies entering calculations. For example, use SUM to total a group of values, such as =SUM(A1:A100).
Enter a formula that refers to values in other cells

In a sheet that contains columns of numbers, click the cell where you want the formula results to appear.

Type an equal sign =

Click the first cell that you want to include in your calculation.

Type an operator. An operator is the kind of calculation that the formula performs. For example, the * (asterisk) operator multiplies numbers. In this example, use the / (forward slash) operator to divide. At this point your formula should look like this:

Click the next cell that you want to include in your calculation. Now your formula should look like this:

Press RETURN.
The result of the calculation appears in the cell.
Tip: To quickly apply a formula to the next cells down in the column, doubleclick the fill handle on the first cell that contains the formula.
Enter a formula that contains a function

In a sheet that contains a range of numbers, click the empty cell where you want the formula results to appear.

Type an equal sign and a function, for example =MIN. MIN finds the smallest number in a range of cells.

Type an opening parenthesis, select the range of cells that you want to include in the formula, and then type a closing parenthesis.

Press RETURN.
In our example, the MIN function returns 11, the smallest number in cells A1 through C4.
Tips
When you enter a formula in a cell, the formula also appears in the formula bar.
Use the shortcuts in the formula bar to help you create formulas:

Select to check your formula. If there are no errors, the cell will display the result of the formula. If there are errors, you'll see . Hover over it for an explanation of the problem, or select the dropdown for additional troubleshooting help.

Select to revert to your previous formula.


To select a function, use the function list.
When you select a function, the Formula Builder opens, with additional information about the function.