Percentages aren't always easy to calculate, but one of the best tools in Excel's toolbox is calculating percentages for you. Here's how to do it.

If you need to find the percentage change in Excel, especially across a range of cells, then this post offers step by step guidance.

Secondly, you can apply a percentage markup to your cost to calculate the maximum sales price. As a third option, you can use margin. Unlike markup, margin is based on the sales price, not the cost.

Warnings If you are not careful in collecting and analyzing the numbers you use to calculate ROI, the percentage Excel calculates will provide a false picture of you business's health.

Learn to calculate Consumer Price Index (CPI) using Excel and create its graph, please read through this article. We have discussed the prcedure extensively.

The article How to Calculate the Regression of 2 Stocks Using Excel originally appeared on Fool.com. Try any of our Foolish newsletter services free for 30 days .