How much fencing material do I need?
Measure each straight run of fence and count its gates. Take the gate openings off the run, divide by the post spacing, and round up to get sections. Each run needs one more post than it has sections, plus one for every gate.
Posts per run = sections + gates + 1, where sections = (run length − gate widths) ÷ post spacing, rounded up
A 100 ft wood privacy fence with one 4 ft gate and posts 8 ft apart: 96 ft of fence makes 12 sections, so you need 14 posts. With 3 rails per section that's 36 rails. 5.5 in pickets set tight take 2.18 per foot, or 220 pickets with 5% extra. In 10 in holes 2 ft deep, the posts take 35 bags of 50 lb fast-setting concrete.
If two runs meet at a corner, they share a post. Enter the number of shared corners and the calculator takes those posts off.
Wood fence calculator
Wood fences use 4×4 posts, 2×4 rails and pickets. Posts are typically 6 to 8 ft apart, and 8 ft lets each rail span one section without a cut. Most 6 ft fences use 3 rails and most 4 ft fences use 2. Post length is the fence height plus the hole depth, rounded up to the next stock length.
| Style | Picket | Spacing | Pickets per foot |
|---|---|---|---|
| Privacy | 5.5 in (1×6) | Tight, no gap | 2.18 |
| Picket | 3.5 in (1×4) | 2.5 in gap | 2.00 |
| Board on board | 5.5 in (1×6) | 1.5 in overlap each side | 3.00 |
Privacy fence calculator
A privacy fence sets the pickets edge to edge with no gap. Fresh pressure-treated pickets shrink as they dry, so small gaps can open up. If you want a gap from the start, enter it in the gap field.
Picket fence calculator
A classic picket fence is about 4 ft high with 1×4 pickets and a gap of 2 to 3 in. Pickets per foot are 12 ÷ (picket width + gap). With 3.5 in pickets and a 2.5 in gap that's 2 per foot.
Board on board fence calculator
Board on board uses two layers. The back layer has gaps, and the front boards cover each gap, overlapping the back boards on both sides. Each board adds its width minus one overlap, so pickets per foot are 12 ÷ (width − overlap). 1×6 boards with a 1.5 in overlap need 3 per foot, about 40% more than a tight privacy fence.
Chain link fence calculator
Chain link has two kinds of post. Terminal posts go at the ends, corners and both sides of each gate. Line posts go between them, typically up to 10 ft apart. Top rail comes in 10 ft 6 in sticks that slip together, and fabric comes in 50 ft rolls. Each terminal post gets a tension bar, tension bands (typically one per foot of height, less one), a brace band, a rail end and a cap. The calculator counts these as one set per terminal post.
Vinyl fence calculator
Vinyl fences come as panels, usually 6 or 8 ft wide, that fit between routed posts. Set the post spacing to your panel width. Each section is one panel, and the last panel in a run may need to be cut down.
How much concrete per fence post?
A common rule is a hole about 3 times the post's width and deep enough to reach below your frost line. For a 4×4 post in a 10 in hole, 2 ft deep, the hole holds 1.09 cubic feet and the post takes up 0.17, leaving 0.92 cubic feet. That's about 2.5 bags of 50 lb fast-setting mix, or 1.5 bags of 80 lb mix. Check the yield on the bag and your local code for post depth.
Pricing a fence job
Fence contractors usually quote by the linear foot, with gates as separate lines. Switch to contractor mode to add your labor and markup, then send it with the fencing estimate template.
Questions
How much concrete do I need per fence post?
For a 4x4 post in a 10 inch hole 2 feet deep, about 0.9 cubic feet: roughly 2.5 bags of 50 lb fast-setting mix or 1.5 bags of 80 lb mix.
How far apart should fence posts be?
Wood fence posts are typically 6 to 8 feet apart, vinyl posts match the panel width, and chain link line posts are typically up to 10 feet apart.
How many pickets do I need for a privacy fence?
With 5.5 inch pickets set tight, about 2.2 per foot of fence. A 100 foot run needs about 220 pickets with 5% extra.
How deep should fence posts be?
Commonly 2 to 3 feet, deeper for tall fences and gate posts, and below the frost line where the ground freezes. Check your local code.