You will need to measure the outside dimensions of your post. The best post cap opening size is going to be 1/16 inch to â…› inch larger than your post. The most common post cap sizes are 4x4 inches and 6x6 inches.
Watch this quick video and if you are still unsure about what size you need, or you can give an expert at DecksDirect a call at 1-888-824-5316. We would be happy to help you find the right post cap for your deck or railing!