Fence Calculator

To estimate a fence, divide the length by the post spacing and round up for sections, then add one post plus one per gate. Rails are sections × rails per section; pickets are the fenced length in inches ÷ (picket width + gap). 150 ft of 6 ft privacy fence at 8 ft spacing takes 21 posts and 319 pickets.

How do you calculate fence materials?

Work from the fence line out: sections from the post spacing, posts from the sections and gates, rails from the sections, pickets from the length you'll actually cover, then post holes and concrete from the post size and fence height.

Posts = ⌈L ÷ S⌉ + 1 + G;  Pickets = ⌈(L − G × Wg) × 12 ÷ (P + gap)⌉

1. 1

   Measure the fence line.

   Walk the line and measure each straight run. Corners, ends and gate posts are fixed points; lay out spacing between them.

2. 2

   Count sections and posts.

   Divide each run by the post spacing and round up. Add one post to close the run and one extra for each gate's latch side.

3. 3

   Count rails.

   Multiply sections by rails per section. Many 6 ft privacy fences use 3 rails; shorter fences often use 2.

4. 4

   Count pickets.

   Subtract gate openings, convert to inches and divide by picket width plus gap. Add a few for culls.

5. 5

   Size the holes and concrete.

   Hole diameter about 3× the post width, embedment half the above-ground height, plus 6 in of gravel. Work out concrete from the hole volume minus the post.

How deep should fence posts be?

QUIKRETE's guidance is to set posts 1/3 of their overall length in the ground, which works out to half the fence height above ground: 36 in for a 6 ft fence on a 9 ft post. Its how-to video gives 1/3 to 1/2 of the above-ground height, with at least 2 ft for a 6 ft fence. Add 6 in for a gravel base. Where the ground freezes, local code or the inspector may require holes below the frost line.

How much fence for common jobs?

What post spacing should I use?

Most wood privacy fences use posts 6 to 8 ft on center, set so 8 ft rails and panels land on posts. University of Georgia Extension's farm fencing guide shows 4-rail board fence with posts spaced 8 ft and line posts set at least 2 ft deep. Tighter spacing adds posts and concrete but stiffens tall fences in windy, exposed yards.

Common fence estimating mistakes

1. Forgetting the extra post. Sections + 1, not sections. Every gate adds a latch post.
2. Using nominal picket widths. A 1×6 is 5.5 in. Using 6 in under-counts by about 8%.
3. Not checking the property line and utilities. Call 811 before digging and confirm the line before setting the first post.
4. Shallow holes. A post with too little embedment leans in the first wind. Follow the 1/3 rule at minimum, deeper where frost or code requires.
5. Skipping hardware and fasteners. Gate hinges, latches, rail brackets and nails or screws are a real line on the quote.