How Far Apart Should Fence Posts Be for a 6 ft Wood Fence?

The 8 ft answer

Space posts 8 ft apart, measured center to center, for a 6 ft wood fence. That gives an 8 ft bay between posts, which matches a standard 8 ft panel or a run of 6 ft pickets spanning two horizontal rails. The 6 ft height and the 8 ft bay are the default dimensions this calculator uses, so leaving both values in place returns post, panel or picket, rail, concrete bag and cost figures for a typical run.

Treat 8 ft as the starting point rather than a rule set in stone. The number comes from how far a rail can span without sagging under its own weight and wind load, and from what suppliers stock. If you buy panels or rails in a different length, set post spacing to match that length rather than forcing 8 ft and cutting every bay down. The calculator takes panel or bay width and post spacing as separate inputs, so you can model either approach before you buy.

Why 8 ft works for 6 ft fences

A 6 ft fence carries two horizontal rails per bay. Each rail spans the full 8 ft between posts and is fastened to both, so the load is shared. The pickets, 89 mm wide with a 13 mm gap, sit on those rails and add little span of their own. At 8 ft, a rail of adequate section holds up without a mid-span support, which is why the bay length has become the trade default in the US.

The height matters too. A 6 ft fence is tall enough to catch wind but short enough that the posts do not need the tighter spacing a taller privacy fence might call for. Going wider than 8 ft is where problems start: rails sag, pickets cup, and the fence looks wavy from the street. Going narrower adds posts, holes and concrete bags without improving the fence. The calculator shows that cost directly, so you can compare an 8 ft layout against a 6 ft one and see how many extra posts and bags the tighter spacing adds.

Worked example: counting posts and concrete

Take a straight 48 ft run. At 8 ft spacing you need 7 posts: one at each end plus one every 8 ft, which gives 6 bays of 8 ft. That is 6 panels, or 6 bays of pickets, and 12 rails at two per bay. Now use the supplied hole size, 254 mm diameter by 762 mm deep, which is roughly 0.039 m³ per hole, and an 80 lb bag yielding about 0.017 m³. Each hole needs about 2.3 bags, so 7 posts need roughly 16 bags, and you should round up to 17 or 18 for spillage.

Tighten the same run to 6 ft spacing and the post count rises to 9, with 8 bays. Posts, holes and concrete all increase by about a third, while panel or picket counts stay tied to total length. Enter both layouts in the fence calculator and compare the material cost line before you commit. The cheaper layout is not automatically the better one if the ground is uneven, which is the next point.

When to tighten spacing

On slopes, keep the 8 ft bay but step the fence rather than following the grade. If the ground falls away sharply, a full 8 ft panel or rail run can leave gaps under the pickets. Many installers shorten bays to 6 ft on steep sections so each step is smaller and the bottom line stays closer to the ground. The calculator lets you set a shorter bay width for those stretches and add the results to the flat run.

Gate posts are the other exception. A gate puts a swinging load and a leaning load on its hinge post, so hinge and latch posts are often set in deeper holes and braced, and the first bay beside a gate is sometimes pulled in tighter than 8 ft. Corner posts and end posts also take more strain than line posts. Confirm the detail with your supplier or installer, since hardware and gate weight vary. Local building departments can tell you whether permits or specific post depths apply in your area.

Spacing drives the post count

Every change in spacing changes the post count, and the post count drives holes, concrete bags and a large share of the cost. The arithmetic is simple: divide the run length by the spacing, round up, and add one for the closing post. A 100 ft run at 8 ft gives 12.5, rounded to 13 bays, so 14 posts. At 6 ft it gives 16.7, rounded to 17 bays, so 18 posts, four more holes and roughly nine more bags of concrete.

Run the numbers before you dig. Set the run length, bay width and post spacing, and let the fence calculator return posts, panels or pickets, rails, concrete bags, gates and a material cost in USD. Check the output against your own sketch, then confirm post depth and concrete quantity with your supplier, because bag yield, soil and local requirements vary.

Checking local requirements

The 8 ft figure is a trade convention, not a legal standard. Frost depth, soil type, wind exposure and permit rules differ across the US, and what holds in one state may not hold in another. Your local building department is the authority on whether a permit is needed, how deep posts must be set, and any height limits. Ask before you order materials.

Your supplier is the authority on what is actually in stock: panel lengths, rail lengths, picket dimensions and bag yield. Delivery times and prices change, so confirm them at the point of purchase rather than relying on a calculator estimate. Use the tool for planning, then verify the specifics locally.

Quick summary

For a 6 ft wood fence, set posts 8 ft on center. Keep that spacing on flat, straight runs, tighten it on steep slopes and around gate posts, and let the resulting post count drive your hole and concrete estimate. Confirm depth, permits and stock with your local building department and supplier before buying.

Frequently asked questions

The answers below cover the details readers ask about most.

Frequently asked questions