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Fence Material Calculator
Enter your fence length and picket size to get posts, pickets, rails, concrete bags — and the total cost.
What a fence is made of
A wood privacy fence is four things: posts set in concrete, horizontal rails, vertical pickets, and fasteners. The posts carry everything, so they are the first number to get right: one post every 8 feet is the standard spacing, plus one extra post at the end of the run. The pickets are the big quantity — a 100-foot fence with standard 5.5-inch pickets needs about 219 of them with no gap, and the count falls if you leave gaps for airflow. Rails are usually two per section for a 6-foot fence and three for an 8-foot fence.
How the numbers work
Posts equal the fence length divided by the spacing, rounded up, plus one for the final post. Pickets equal the total length in inches divided by the picket width plus the gap, rounded up. Rails equal the number of sections — one less than the post count — times the rails per section. Concrete is estimated per post: 1.5 bags of 80 lb mix is typical for a standard post hole, but corner posts, gate posts and wet ground need more. The cost line simply multiplies each quantity by the unit price you enter.
Before you order
Check your local rules first: many areas limit fence height, require a permit above 6 feet, and require the finished side to face the neighbour. Call 811 or your local utility locator before you dig — hitting a buried line is the most expensive mistake in fencing. Buy 5–10% extra pickets for warped boards and cutting mistakes, and buy your posts a grade up from the pickets: posts rot first, and replacing a post means rebuilding the section around it.
Frequently asked questions
How many fence posts do I need for 100 feet?
With standard 8-foot spacing you need 14 posts: 100 ÷ 8 = 12.5 sections rounded up to 13, plus one end post. Enter your exact length above — the calculator does this for any run.
How many pickets for a 100 ft fence?
About 218 pickets at 5.5 inches wide with no gap. With a 1-inch gap for airflow the count drops to about 185, but the fence is no longer fully private. The calculator adjusts for any picket width and gap.
How much concrete per fence post?
About 1.5 bags of 80 lb mix for a standard 10-inch diameter hole 2 feet deep. Gate posts and corner posts usually need 2 bags. In loose or wet soil, budget more.
Last updated 2026-11-09. Results are estimates for planning only — always confirm with the official source before spending money or signing anything. This tool runs entirely in your browser; nothing you type or upload leaves your device.