How To Measure Pipe Size. Now you can take your dimensions and run to your local hardware store to purchase the correct size fitting. The diameter of a pipe is the distance between one wall of the pipe to the other wall of the pipe going through the center of the pipe.
How do you measure pipe size? Use a ruler or measuring tape to find the length between the tip of the string and the mark you made (circumference) divide the circumference by 3.14159; Using the proper pipe thread type is crucial for maintaining and installing equipment, so helping you determine what pipe thread you need is important to us.
Use this measurement and a dimensional chart to find the pipe's nominal dimension.
Measure the outside diameter (od) of your pipe or pipe fitting: Wrap a string around the pipe. Using the proper pipe thread type is crucial for maintaining and installing equipment, so helping you determine what pipe thread you need is important to us. Find figure nearest this dimension in column 1 or 2 of chart.