Conditional Formatting

New Contributor
Hi All,

Is it possible to conditional format a cell to change colour when it is less than half of another cell. For example.

Cell A1 total is 11
Cell A2 total is 25

I want A1 to colour red if it is less than half of cell A2.

Hope that makes sense.
6 Replies


Yes, you have to use a formula as the Rule Type. See the screenshot:



That's great, and if I was to do the opposite, everything above half to turn green, how would the formula look like? Sorry but I'm so new to this 🤦


You would change the less than sign "<" to greater than ">" in the formula and click on "Format" to modify the background color. 

And if A1 was exactly half of A2 for example,
A1 11
A2 22

Would I show it as


No, the "<>" symbol means when A1 does not equal to A2. To get an exactly half condition would mean adding the "=" to the greater/less than sign.


For example, if you want A1 less than or equal to 1/2 of A2, the formula would be:

A1 <= A2/2

Thank you so much for this. Much appreciated