Purchase your conduit first. PVC conduit may be easier to work with and bend, if it becomes necessary.
Look for a smaller type of conduit. The smaller the conduit, the easier it will be to fit into the Wiremold product.
Measure your conduit with a tape measure. Wrap it around the piping so you get an accurate measurement.
Select a Wiremold product that fits well with your conduit. Take a piece of conduit and your measurements to the store if you're buying the Wiremold in person. Otherwise, read the website closely for sizing on the Wiremold connection.
Test your conduit on the Wiremold. Bring the conduit through the back, if possible. Look for a smaller conduit or larger Wiremold connector if they aren't compatible.