How To Calculate Valid Percent

The valid percent is simply the proportion of a sample that is valid. Data can be invalid for a variety of reasons. Some data are simply impossible, such as negative heights or weights. Some data can be shown to be invalid by comparing them with other data. For example, a person might be two years old, and a person might be a widow. But it is hard to conceive of a person who is a two year old widow! Finally, some data can be identified as machine error or data entry error.

Step 1

Write down the total sample size. For example, you might have 1000 cases.

Step 2

Write down the number that are invalid. For example, there might be 92 invalid cases for one reason or another.

Step 3

Subtract the result in step 2 from that in step 1. For instance 1000 – 92 = 908.

Step 4

Divide the result in step 3 by the result in step 1 and multiply by 100. 908/1000 = .908. .908*100 = 90.8. Therefore 90.8 percent of our data are valid.