Fence Material Calculator
Enter your fence length and height to get an exact count of posts, rails, pickets and concrete bags — with a materials list you can take to the store.
How the fence material calculator works
Estimating fence materials by hand is easy to get wrong — an off-by-one on posts or a bad picket count means a second trip to the lumber yard mid-project. This calculator turns four numbers (length, height, post spacing and picket width) into a complete take-off so you can price the job and buy once.
Posts
The tool divides your total run by the post spacing to get the number of sections, then adds one. A 100-foot fence at 8 feet on center is 13 sections, which needs 14 posts (every section shares a post with the next, but both ends need their own). Corners and gates need an extra post each — add those manually if your layout has them.
Rails
Each section gets the number of rails you choose. Use 2 rails for fences up to about 4 feet, 3 rails for a standard 6-foot privacy fence, and 4 rails for 8-foot fences to stop the pickets from warping. The calculator reports both the number of rail boards (one section long each) and the total linear feet of rail, so you can buy whichever way your supplier sells them.
Pickets
Picket count is the part people get wrong most often. The tool works in the real width each picket occupies — its face width plus the gap. For a solid fence with 5.5-inch pickets and no gap, that is 5.5 inches per picket, so 100 feet (1,200 inches) needs 219 pickets. Add a 1.75-inch gap for a shadowbox/spaced look and the same run drops to 166 pickets. Change either number above and the count updates instantly.
Concrete
The materials list includes a fast concrete estimate assuming 8-inch-diameter, 24-inch-deep holes with a 4×4 post — roughly one to two 60-pound bags per post. Hole size drives concrete more than anything, so if you are digging wider or deeper holes (frost line, tall fences, gates), run the numbers through the dedicated fence post concrete calculator for an exact bag count.
Tips before you buy
- Measure the real run. Walk the line with a tape or wheel; property-line assumptions are often off by several feet.
- Account for slope. On a hill you either "rack" panels or step them — either way pickets and rails go up slightly. Add 5–10%.
- Buy pickets from the same batch. Color and moisture vary between deliveries; mixed batches show once stained.
- Check post length. A 6-foot fence with 24-inch-deep holes needs 8-foot posts, not 6-foot.
This tool is for planning estimates only. Local codes govern setbacks, height limits, post depth and whether a permit is required — confirm with your local building department before you dig.
Frequently asked questions
How many fence pickets do I need per foot?
It depends on picket width and gap. For a solid privacy fence using 5.5-inch (nominal 1×6) pickets with no gap, you need about 2.2 pickets per linear foot. For a spaced picket fence with a 1.75-inch gap you need about 1.65 per foot. This calculator does the exact count for your picket width and gap.
How far apart should fence posts be?
Most wood fences use 6 to 8 feet between post centers. 8 feet is common and economical, but windy areas or heavy panels do better at 6 feet. Pre-made panels force the spacing — usually exactly 8 feet on center.
How many rails does a fence need?
Use 2 rails for fences up to about 4 feet tall and 3 rails for 6-foot fences. Taller than 6 feet, add a fourth rail to keep pickets from cupping.
Does the calculator include concrete for the posts?
Yes — it gives a quick estimate based on 8-inch-wide, 24-inch-deep holes with a 4×4 post. If you are using bigger holes or 6×6 posts, use our dedicated Fence Post Concrete Calculator for an exact bag count.
Should I buy extra material?
Add about 10% for pickets and rails to cover cuts, defects and mistakes. Posts are counted exactly, but buying one spare post is cheap insurance.