Conditional formatting if cells are within a range of each other

Question

Using Excel 2013. I have a long list of numbers in column A. I would like to conditionally highlight any cell that is in a range of +/- 5 with respect to the number above it OR the number below it.

For example, if I have 1, 1, 10, 20, 21, 22, 50 (in this order) the cells highlighted should be the ones containing only 1, 1, 20, 21, 22.

Answer 1

Please try:

=OR(ABS(A1-A2)<6,ABS(A2-A3)<6)  

The maximum difference allowed is +/-5 which is a little simpler to express in a formula as not as much as +/-6, hence <6 in conjunction with ABS because of the +/-, ie the sign of the difference is not relevant. There are two possibilities (hence the OR), in the example A2 needs to be compared with both A1 and A3.

It is the nature of Conditional Formatting that it automatically steps through the relevant Applies to range, and applies the formula to each cell in turn. Just like the formula shown in a cell and copied down one row would automatically adjust to =OR(ABS(A2-A3)<6,ABS(A3-A4)<6), so for CF.

If the formula in the cell were =OR(ABS($A$1-$A$2)<6,ABS($A$2-$A$3)<6) before copying the result in another cell would not differ (because the references have been fixed – with $s). So with CF – with $ throughout then the entire Applies to range would be formatted according only to the values in A1:A3.

The same options for use of $ are available in CF as in a cell – ie making references absolute ($) can be mixed with relative, both in different parts of a formula and within a single cell reference (ie Column and Row independently).