20x20 Pergolas

20x20 Refers to the Combined Inner Dimensions of the 4 Roof Openings

When we say a pergola's dimensions are 20x20, we are referring to the combined inside dimensions of the 4 roof openings (from inside-edge to inside-edge). All of the kits featured on this page are meant to have 4 roof openings, arranged in a 2x2 grid, which combine to be a total of 20' wide and a total of 20' deep.

The overall outside-edge to outside-edge dimensions of the pergola will be:

• 21' 2.6" wide x 21' 2.6" deep (if you choose a kit for 4x4 posts) OR
• 21' 10.6" wide x 21' 10.6" deep (if you choose a kit for 6x6 posts)

With all of this being said, you can easily change the overall size of your pergola by trimming the wood posts that you plan to use for the roof beams. For example, if you wanted the true outside-edge to outside-edge dimensions of a free-standing pergola to be exactly 20' x 20', you would need to:

• Purchase three sets of two posts totaling 20 feet to be the beams running the 20-foot width, and then cut off a total of 14.6 inches (for 4x4 wood posts) or 22.6 inches (for 6x6 wood posts) per set of two posts; and
• Purchase three sets of two posts totaling 20 feet to be the beams running the 20-foot depth, and then cut off a total of 14.6 inches (for 4x4 wood posts) or 22.6 inches (for 6x6 wood posts) per set of two posts

Important Note: Our shade canopies are specifically designed to fit roof openings that are exactly 8x8, 8x10, 8x12, 10x10, 10x12 and 12x12. If you're purchasing a kit with shade canopies, you cannot trim down the roof beam posts. Furthermore, all roof posts must be 8-, 10- or 12-foot lengths.