Chain Link vs Wood Fence Post Spacing in the US

The short answer on spacing

Wood fence posts are set at 8.00 ft on center, because each bay holds one 8.00 ft panel or a run of pickets cut to that span, with two horizontal rails per bay. Chain link line posts are commonly set at 8 to 10 ft, and the spacing you can actually use depends on the manufacturer's post and rail specification for your wind load. Terminal posts, the heavier posts at corners, ends and gate openings, are braced rather than spaced evenly, so they do not follow the line post interval. Confirm the chain link interval with your supplier's spec sheet and your local building department before you dig.

The practical difference is small on a straight run but matters at corners, gates and changes in grade. A wood layout snaps to 8.00 ft bays; a chain link layout can stretch to 10 ft, which reduces post count and concrete. Neither number is a rule you can apply blind, because local codes and manufacturer instructions govern.

Wood posts, bays and concrete

Using the calculator defaults, a 48.00 ft straight run at 8.00 ft spacing gives 7 posts counting both ends, 6 bays, and 12 rails at two per bay. Pickets at 89 mm wide with a 13 mm gap cover about 102 mm each, so an 8.00 ft bay needs roughly 24 pickets, and the full run about 144. That is the arithmetic the calculator handles for you once you enter the run length.

Each post hole is 254 mm diameter by 762 mm deep, about 0.0386 m³ of hole volume. An 80 lb bag yields about 0.017 m³, so one hole takes roughly 2.3 bags, and 7 posts take about 16 bags. Round up to 17 or 18 for spillage and uneven holes. Set posts below the local frost depth, which varies by region, and check the depth requirement with your local building department. Wood posts in direct soil contact also need a ground-contact rated material; ask your lumber supplier which treatment suits your area.

Chain link line and terminal posts

Chain link separates line posts from terminal posts. Line posts carry the mesh between terminals and are the ones set at the 8 to 10 ft interval. Terminal posts, at corners, ends, gate jambs and any pull point, take the tension of the fabric and are braced with a horizontal rail or diagonal truss back to the adjacent line post. A 48.00 ft run with terminals at both ends and line posts at 8.00 ft gives 2 terminal posts and 5 line posts, or 7 posts total, the same count as wood at that spacing.

Stretch to 10 ft and the same run needs 2 terminals and 4 line posts, one fewer hole. The savings are modest but real: one fewer post, one fewer hole, and about 2.3 fewer bags of concrete. The catch is that longer spans need heavier posts and rails to carry wind load, so confirm the interval against the manufacturer's specification rather than assuming 10 ft is always allowed.

Concrete and cost compared

Concrete is where the two systems diverge least. A 254 mm by 762 mm hole is the same for either post type, so at 7 posts you need about 16 bags of 80 lb mix, and the calculator's bag count stays the same unless the hole size or post count changes. What changes is the post count per foot of fence, and therefore the number of holes.

For cost, enter your local post, panel or picket, rail, gate and bag prices into the calculator and compare the two totals for the same run. Prices vary widely by region and supplier, so get quotes from at least two yards. Do not carry a price from one market into another; a figure that holds in one state may be well off in another. The comparison that matters is your own quoted prices against the same run length and the same hole count.

What to confirm before digging

Call 811 before any digging so utilities are marked, and check your local building department for permit thresholds, height limits and frost depth. In areas with high wind exposure, the chain link interval and post weight must follow the manufacturer's engineering, and wood posts may need closer spacing or deeper holes than the defaults. Ask your supplier for the specification sheet in writing.

For gates, remember that gate posts are terminal posts in both systems and are set at the gate width, not the bay width. The calculator returns gates separately so the opening is not mistaken for a standard bay. If your run does not divide evenly, the last bay is shorter; keep the spacing even and absorb the remainder at one end rather than stretching every bay.

Worked example: 48 ft run

Take a 48.00 ft straight run with no gates. Wood at 8.00 ft spacing: 7 posts, 6 bays, 12 rails, about 144 pickets, about 16 bags of concrete. Chain link at 8.00 ft: 2 terminal posts and 5 line posts, 7 holes, about 16 bags. Chain link at 10.00 ft: 2 terminal posts and 4 line posts, 6 holes, about 14 bags.

The difference between the two chain link layouts is one post and about 2.3 bags, which is why the spacing decision is mostly about the manufacturer's wind rating and local code, not about saving concrete. Run your own length through the fence calculator to get posts, panels or palings, rails, bags and a material cost from your quoted prices.

Frequently asked questions

Can wood and chain link share the same post spacing? At 8.00 ft they can line up, but the posts are not interchangeable. Wood posts carry rails and pickets; chain link line posts carry tensioned fabric and need terminal bracing at ends and corners. Do not substitute one for the other without checking the manufacturer's specification.

Do terminal posts count toward the spacing interval? No. Terminal posts sit at corners, ends and gate openings and are braced to the nearest line post. Measure the line post interval between terminals, not through them.

How many bags of concrete per post? At 254 mm by 762 mm, about 2.3 bags of 80 lb mix per hole. Round up and confirm the mix and hole depth with your local building department and supplier.

Does frost change the hole depth? Yes. Depth requirements vary by region, so check with your local building department before digging. Deeper holes need more concrete, which the calculator will reflect once you change the depth.