Pergola Post Size 4×4 or 6×6: Which One is Best for Your Project?
For a pergola with about 4 to 6 feet between posts and under 3 feet from the ground, 4×4 posts will be sufficient. However, experienced contractors generally recommend 6×6 posts as 4×4 posts will be unable to carry as heavy a load as most porches require, and may warp and bend over time, causing a safety concern.