Fence Calculator
Enter your fence length, height and gates to get post counts, pickets or panels, rails, post-hole concrete and a materials cost. Every price is editable.
How this fence calculator works
Sections and posts: the tool takes your fence length, removes the gate widths, and divides by your post spacing (8 ft by default), rounding up. An open run has one more post than it has sections. Each gate adds a post, and every corner, end and gate post is counted as a heavier post.
Pickets: for a regular privacy fence the pickets per foot is 12 ÷ (picket width + gap). With 5.5 in boards and a 1/4 in gap that is 2.09 per foot. For board-on-board the pickets per foot is 12 ÷ (board width − overlap), because two layers share the run. With 5.5 in boards and 1 in overlap that is 2.67 per foot.
Rails: 2×4 rails run between posts: 2 for fences up to 4 ft, 3 for 5 to 6 ft, 4 for 8 ft. Chain link has a top rail and rolls of fabric 50 ft long. Vinyl panels are one per section.
Post holes: the common rule is a hole about three times the post width, with about one-third of the post length in the ground and at least 2 ft. Concrete is the hole volume minus the post, divided by 0.60 cubic ft per 80 lb bag. Auto post length picks the shortest stock length that leaves your fence height above ground.
Check these before you build
- Property line survey: know exactly where your line is.
- HOA and deed restrictions: height, style and color are often limited.
- Call 811: it is free and prevents hitting gas, water, electric and fiber lines.
- City rules: fence height limits and permits vary by city, so ask your building department.
Prices are planning numbers. Published 2026 installed ranges are roughly $28 to $50 per ft for a 6 ft wood privacy fence, $30 to $60 for vinyl privacy, and $32 to $71 for chain link (the typical job around $44), which include labor.
Sources
Estimates only — not engineering, legal or code advice. Check requirements with your local building department and a licensed professional before you build.
Common questions
How many fence posts do I need for 100 feet of fence?
With posts 8 ft apart, 100 ft makes 13 sections (100 ÷ 8, rounded up). A straight open run has one more post than sections, so you need 14 posts. Each gate adds a post, and corners and ends need heavier posts.
How many pickets per foot for a privacy fence?
Divide 12 inches by the picket width plus the gap. For 5.5 in (1×6) pickets with a 1/4 in gap that is 2.09 pickets per foot. A 116 ft run (120 ft less a 4 ft gate) needs 262 pickets with 8% waste. Board-on-board overlaps two layers: with 5.5 in boards and 1 in overlap it takes 2.67 boards per foot.
How deep should fence posts be set?
A common guideline is to bury about one-third of the post length, at least 2 ft, in a hole about 3 times the post width. For a 6 ft fence this tool picks a 10 ft post, which puts 4 ft in the ground. Loose or sandy soil may need more depth, and your building department may set its own rule.
How many bags of concrete per fence post?
For a 4×4 post in a 10.5 in hole 48 in deep, about 3.4 bags of 80 lb concrete. A 6×6 post in a 16.5 in hole needs about 8.5 bags. Choosing a narrower 2× hole (8 in for a 4×4) cuts that to about 1.8 bags. Concrete is often the biggest hidden cost, so test the hole rule before you buy.
How many rails does a 6 ft fence need?
This tool uses 2 rails for fences up to 4 ft, 3 rails for 5 to 6 ft and 4 for 8 ft. Rails are 2×4s between posts, and posts should be no more than 8 ft apart so the rails do not sag.
What should I check before building a fence?
Get a property survey so you know the line. Read your HOA or deed restrictions. Call 811 (free) before you dig so utilities can mark buried lines. Ask your building department about height limits and permits. Then make sure the good side faces out where your rules say.