Fence Calculator

Plan out a fence build without making three trips to the lumberyard. Enter total length, fence type, post spacing, and number of gates — we'll tell you how many posts, panels, rails, and concrete bags you need, plus a quick cost estimate.

Tips for Estimating Fence Materials

Most fence calculators undercount posts. Remember: a 150 ft fence with 8 ft spacing isn't 150 ÷ 8 = 19 posts — it's 19 + 1 = 20, because you need a post at both ends. Same logic applies to every corner and gate post. Always order 10% extra panels and 1–2 extra posts as backup; they're cheap insurance against a warped board or a botched concrete pour.

If your run isn't a clean multiple of the panel size, the last panel will need to be cut. Buy a full-length panel for that section anyway — partial panels are rarely sold and cuts are easier than splices.

How This Calculator Works

The calculator works in fence sections. First it sets aside room for gates: each gate takes up one section width, so the fenced run is your total length minus gates times section spacing. The remaining run is divided by your post spacing (8 ft is standard for panels) to get the number of panels, then padded by your waste factor and rounded up.

Posts follow the line-post rule: a straight run needs one more post than it has sections, plus an extra post for each gate to hang on. Rails default to three per section — top, middle, and bottom — which suits most privacy and ranch styles. Concrete is figured at two bags per post for a properly set footing. Cost adds it up: panels × panel price, plus posts × post price, plus gates × gate price.

A Worked Example

Fencing a 200 ft backyard run with 8 ft spacing, one gate, and 5% waste. Subtract the gate: 200 − (1 × 8) = 192 ft of paneled fence. Divide by 8 = 24 sections, padded 5% and rounded up to 26 panels. Posts: 26 + 1 + 1 gate post = 28. Rails: 26 × 3 = 78. Concrete: 28 × 2 = 56 bags. With pressure-treated panels near $95, posts near $22, and a gate kit near $140 in 2026, the material runs about 26 × $95 + 28 × $22 + 1 × $140 = $3,226.

Estimator's tip: Set your corner and gate posts first and let the concrete cure a day before you hang anything heavy — those posts carry all the load and tension. On a sloped yard, decide early whether you are racking the panels to follow the grade or stepping them in level sections, because stepping adds posts and partial panels the straight-run math here does not assume. Pull a string line; eyeballing post spacing always drifts.

What Affects Your Material List

• Post spacing — tighter spacing (6 ft) means more posts and panels but a sturdier fence in wind.
• Number of gates, since each one removes a panel and adds a heavier-duty post.
• Corners and direction changes, which each need an extra post the straight-run math does not add.
• Waste factor for cut panels on slopes and at terminal ends.
• Footing depth and your frost line, which decide how much concrete each post actually swallows.
• Terrain: stepping a fence down a slope adds posts and partial panels.

Frequently Asked Questions

How many fence posts do I need?

For a straight run, take the number of sections and add one, then add a post for every gate. An 80-foot fence at 8-foot spacing is 10 sections, so 11 line posts plus any gate posts.

What is standard fence post spacing?

Eight feet on center is standard for pre-built panels and most wood privacy fence. Drop to 6 feet for high-wind areas, heavy gates, or where local code requires it.

How much concrete per fence post?

Budget about two 50-pound bags of fast-setting concrete per post for a typical 8 to 10-inch hole set below the frost line. End and gate posts often take more.

How do gates affect the material count?

Each gate replaces one fence section and needs its own reinforced post to carry the swing, so the calculator subtracts a panel and adds a post for every gate you enter.