How to estimate fence materials
Every fence comes down to posts and what hangs between them. Count the sections first and everything else follows. Here is the math for the calculator's default: 100 ft of 6 ft treated-pine privacy fence with two corners, one 4 ft gate and posts 8 ft apart.
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1
Take out the gates
One 4 ft gate leaves 96 ft of fence. Two corners split it into three runs of 32 ft.
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2
Count sections and posts
Each 32 ft run divided by 8 ft is 4 sections, so 12 sections in all. Posts are sections plus one, plus one more for each gate opening: 12 + 1 + 1 = 14 posts. Corner posts are shared by two runs, so they're already counted.
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3
Pick the post length
Bury about a third of the post, which is half the fence height and never less than 2 ft. A 6 ft fence needs 3 ft holes, so each post is 9 ft long. Buy 4x4x10 and trim the tops level.
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4
Work out the concrete
A 10 in hole 3 ft deep holds 1.64 cubic feet. The post takes up 0.26, leaving 1.38. Times 14 posts plus 10 percent extra is 21.3 cubic feet. At 0.375 cubic feet per 50 lb bag of fast-setting mix, that's 57 bags, about four per post.
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5
Add rails and pickets
A 6 ft fence gets three 2x4 rails per section: 36 rails. Butted 5½ in pickets need 96 × 12 ÷ 5.5 = 209.5 for the fence, 220 with 5 percent extra, plus 9 for the gate: 229 in all.
Post spacing and depth
Closer posts make a stiffer fence. Deeper posts resist wind and frost. These are the usual numbers for residential fences.
| Fence | Post spacing | Hole |
|---|---|---|
| Wood, stick-built | 6 – 8 ft | 10 in wide, ½ fence height deep |
| Wood panels | 8 ft (panel width) | 10 in, ½ height |
| Vinyl | 6 or 8 ft | 10 – 12 in, ½ height |
| Chain link | up to 10 ft | 8 in line, 10 in end posts |
| Aluminum | 6 ft (panel width) | 8 in, ½ height |
The hole should be about three times the post's width. In cold climates, go below the frost line for gate posts at least. A heaved gate post is the most common reason a gate stops latching.
Concrete per post
Bags per 4x4 wood post, with the post's own volume taken out and no extra added.
| Hole | Fast-set 50 lb | Regular 80 lb |
|---|---|---|
| 10 in x 2 ft | 2.5 bags | 1.5 bags |
| 10 in x 2½ ft | 3.1 bags | 1.9 bags |
| 10 in x 3 ft | 3.7 bags | 2.3 bags |
| 12 in x 3 ft | 5.6 bags | 3.5 bags |
Fast-setting mix goes into the hole dry, then you add water. It's the easy choice for a few posts. Regular 80 lb mix costs less per cubic foot and gives you more time to plumb each post, which helps on a long run. Our concrete calculator has a column mode for odd hole sizes.
What a fence costs
The default 100 ft treated-pine privacy fence comes to about $1,900 in materials at October 2026 prices, or roughly $19 per foot, with concrete and gate hardware included. Cedar pickets add about $300. HomeGuide's 2026 survey of installed prices, materials and labor together:
| Fence type | Per foot, installed | 100 ft |
|---|---|---|
| Chain link | $10 – $40 | $1,000 – $4,000 |
| Wood | $20 – $50 | $2,000 – $5,000 |
| Aluminum | $25 – $75 | $2,500 – $7,500 |
| Vinyl | $30 – $60 | $3,000 – $6,000 |
A fence is one of the friendlier DIY jobs: no permit in many towns under 6 ft, and mistakes are fixable. Digging is the hard part. Rent a one-person auger for long runs or rocky soil. Hire out when the line is on a slope, when you need to cut through roots or rock, or when the fence is a pool barrier that has to pass inspection.
Tips before you dig
- Call 811 a few days ahead. Utility marking is free, and a fence line crosses more buried lines than you'd think.
- Know where the line is. Find your survey pins or plat before you set posts. Many towns and HOAs also limit height, style and setback, and want the finished side facing out.
- Set the end and corner posts first. Run a string between them and set the line posts to it. Measure spacing center to center for stick-built fences, and dry-fit for panels, since panel widths vary by a fraction of an inch.
- Slope the concrete away from the post. Crown the top so water runs off, and put a few inches of gravel under wood posts so the end grain isn't sitting in a cup of water.
- Use ground-contact posts. Treated posts must be rated for ground contact (UC4A or better). Above-ground lumber rots at the soil line in a few years.
- Build gates last and give them a brace. A wood gate needs a diagonal brace running up from the bottom hinge corner. Vinyl gates need the aluminum stiffener in the hinge post.
Sources and assumptions
Counts use straight runs of equal length between corners, 4 ft gates, and posts set in concrete. Prices are US retail prices checked in October 2026, and the main price for each fence type can be edited.
- Post depth and hole size follow common practice: a third of the post's length in the ground and a hole three times the post's width. See HGTV's guide to fence post depth. Local code and frost depth come first.
- Concrete yields are 0.375 cubic feet per 50 lb bag of fast-setting mix and 0.60 per 80 lb bag of regular mix, as printed by Quikrete, with 10 percent extra.
- Material prices are October 2026 list prices at Menards: 1x6x6 dog-ear pickets $2.48 treated and $3.78 cedar, 6x8 dog-ear panels $79.98 treated and $109 cedar, 4x4x10 treated posts $18.99, 2x4x8 $7.59, 6x8 vinyl privacy panel $119, 4 ft chain link fabric $119 per 50 ft, 4x6 aluminum panel $87.59, fast-setting concrete $7.97.
- Installed prices per linear foot are from HomeGuide's fence installation cost guide (February 2026).
- Fasteners assume two exterior screws per picket at each rail and about 500 screws per 5 lb box. Rails hang in galvanized rail brackets.
Common questions
How many fence posts do I need for 100 feet?
With posts 8 feet apart, a straight 100 ft fence has 13 sections and 14 posts. Each gate adds a post, and corners add one when the runs don't divide evenly by the spacing. A 100 ft fence with two equal runs of 32 ft, one more of 32 ft and a 4 ft gate also comes to 14.
How many bags of concrete per fence post?
A 4x4 post in a 10 inch hole 3 feet deep takes about 1.4 cubic feet of concrete. That is roughly four 50 lb bags of fast-setting mix or two and a half 80 lb bags of regular concrete. A 2 foot hole needs about a third less.
How deep should fence posts be?
A common rule is to bury about a third of the post's total length, which works out to half the fence height and never less than 2 feet. A 6 ft fence needs holes about 3 ft deep. Go below the frost line for gate posts in cold climates.
How far apart should fence posts be?
Wood privacy fences use posts 6 to 8 feet apart, and prebuilt panels set the spacing at their width, usually 8 feet. Chain link line posts go up to 10 feet apart. Aluminum and most vinyl panels are 6 or 8 feet wide.
What is the cheapest fence to build?
Chain link is the cheapest common fence, at about $10 to $40 per linear foot installed. A pressure-treated wood privacy fence runs about $20 to $50 per foot, vinyl $30 to $60 and aluminum $25 to $75, according to HomeGuide's 2026 figures.
How many pickets do I need for an 8 foot section?
Standard 1x6 pickets are 5.5 inches wide. An 8 ft section is 96 inches, so a privacy fence with no gaps takes 18 pickets. With 2.5 inch gaps, a classic picket fence takes 12.