To calculate the square root of a number in Microsoft Excel, enter "=SQRT(number)" into a blank cell. You can also set up side-by-side columns using the Excel worksheet function, where you can enter a number in one column and the square root appears in the column next to it.
- Set up the output column
To set up the output column, type "=SQRT(" into a blank cell, and use your mouse to left-click the cell immediately to the left of the cell you are typing in. Complete the function by typing ")." An example of a formula might be "=SQRT(A1)" if you are typing in cell B1.
- Copy the formula
Click on the cell that you have set up with the square root function. Click Edit and then Copy. Select any number of rows below the copied cell. Click Edit and then Paste Special. Select Formula. The formula is pasted and applied to all selected cells.
- Enter the original numbers
Enter the numbers that you want to find the square root for in the column immediately to the left of the column with the square root formulas. Only positive numbers may be entered. The square root of each number immediately appears in the output column.