Calculating the absolute value of a number strips it of any negative signs, which means the absolute value can only be zero or a positive number. As an example, the absolute value of -100 would just be 100. In Excel, calculating the absolute value is made possible with the ABS function. When encased in this function, any number or equation will be returned as a positive number.
Open a spreadsheet in Microsoft Excel.
Locate the number or equation for which you need to calculate the absolute value. Alternatively, click a cell where you wish to enter a new calculation.
Encase the number or equation with "=ABS(" on it's left side, and ")" on its right side. For example, to calculate the absolute value of -100, enter "=ABS(-100)" in the cell. For the equation "=SUM(A1+A2+A3)," enter "=ABS(SUM(A1+A2+A3))" in the cell.