The actual thickness of these lumber posts is something like 3.5×3.5 in.
As long as your hanging distance is in the ballpark of 14.5 feet and you maintain symmetry on the overhang of the 2×6 cross boards, you’ll be in good shape.
Remember that hammocks are symmetrical, and you may lay in one facing either of your support poles.
The 4×4 posts will stand about 14.5 ft apart, closely mirroring the length of a standard hammock stand built for a 13 ft hammock.
Standard hammocks generally have 12 inches of chain to allow for some adjustment in order to attain the most comfortable hanging height and hammock bed tension.
The rings of the hammock should also be hung about 3 feet 7 inches off of the ground (mirroring the hanging height of popular hammock stands).
Once you have determined your 4×4 post placements, you’re ready to dig the holes into which they will be mounted with concrete.
The 16ft long 2×6 boards will attach on opposite sides of each post (with about 6 inches of overhang) in order to create the classic pergola look.
Keep in mind that 4x4s run smaller than their stated dimensions — the only measurement from the hardware store that should prove 100% accurate is the lumber length.
The foundation of this project rests upon two 10 ft 4×4 wooden posts.
Your hammock will hang between these posts, so keep that in mind as you consider where to begin this project.
But without sturdy, hang-worthy trees, your options are fairly limited.
If you’re the DIY type, you may be interested in this guide to building a simple pergola that can safely support your hammock — and look good doing it!