I'm trying to figure out how to add an equation in a cell which will give me the percentage of a number the difference between two numbers is. For example:

Cell A1: 154
Cell B1: 150

If I use this equation: 150 - 154, the answer is -4. What I need is an equation to give me what percentage of Cell A1 is Cell B1 - Cell A1. If that makes sense.

I've tried B1-A1/A1*100 and it gives me 50, but it's clearly not 50%.

I know it seems simple, but I can't seem to make it work for some reason.

Thanks.