I'm setting up a spreadsheet so I can calculate all my ballistic information from my chronograph. The formula I need help with is to calculate the deviation from the average velocity. I'm trying to use the subtraction formula but depending on the actual veloctiy of the shot it may come up a negative value. I need them to all show a positive value because the avg. deviation formula is the sum of differences of the actual velocity from the average velocity. Ex: Avg vel.=550.3 Actual velocity: 568.6 Deviation would be 18.3 538.0 deviation would technically be -12.3 but I need it to show +12.3 Hopefully I explained this right.