The root mean square (RMS) is a mathematical function with applications in electronics, engineering, and other fields. It’s a difficult value to compute by hand, but Excel spreadsheets make it easy, thanks to a few quick formulas. Let’s learn how to calculate RMS in Microsoft Excel.
How to Calculate RMS in Excel
Root mean square, or RMS, can be found using a few quick steps in Excel. RMS is defined as the square root of the mean of squared values. To find it in Excel for a given dataset, you’ll first need to square the values in your dataset.
In our example, there is sample data in the range A1:A5. To find the squares, click into cell B1. Type an = sign to begin a formula, then type:
Hit Enter, and Excel will return the square value, 4. Then, copy your formula down into cells B2:B5. This squares the remaining values.
Next, you need to find the average of the squares. You can do this anywhere, but we’ll use cell C1. In cell C1, enter the formula:
Hit Enter, and the mean value of the squares is returned: 44.
To find the RMS, you’ll need to finish by finding the square root of the average value returned in cell C1. In cell C2 (or any empty cell), insert the following formula:
Hit Enter once again, and Excel returns the RMS for your dataset: 6.633249581.
As you can see, Excel makes it easy to return the root mean square, or RMS, for a given dataset. Although there isn’t a built-in function specifically for root mean square, it’s simple to compute by using the basic square, mean, and square root formulas that Excel has included. Follow these simple steps and you’ll be able to calculate the RMS for even the largest datasets quickly.