For most people, nail size won't matter for average household repairs. In some instances though, certain size nails need to be used. If this is the case and you aren't sure what size nail you have, here are a few ways to find out.
Step 1- Understand Sizing
While there isn't a set standardization of nails in the industry, most manufacturers will stick to the standard penny sizing. The higher the penny number, the larger the nail is. A 6 penny nail is one of the most common, but nails can also be found in sizes from 2 penny all the way up to 60 penny. You can check the nail head for these numbers. Penny is abbreviated as D, so a nail with 12D stamped will be a 12 penny nail.
Step 2- Find an Online Chart
You can find charts online that describe the sizing, length, head size, and gauge of different nails. If your nail has no markings on it, you may have to start measuring and comparing the measurements with an online chart. As an example, a nail that is 3 inches in length with a 5/16th head is probably a 10 penny nail.