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Fence calculator

Enter the fence length, post spacing, gates and corners, and the style. You get posts, rails, pickets or panels, concrete bags for the post holes, and the cost if you add prices.

Layout

Including gate openings.

Usually 6–8 ft.

Style

A 1×6 is 5.5 in.

0 for a privacy fence.

Post holes

A 4×4 is 3.5 in.

QUIKRETE: 3 × post width.

⅓ of post length; gravel below.

Prices (optional)

Fence materials

23 posts146 ft of fence in 21 sections, plus 1 gate

Rails
63
Pickets or boards
319
Concrete per post
1.38 cu ft (2.3 bags)
80 lb concrete bags
53

Counts rounded up, with no extra for culls. Concrete excludes the gravel base; bag yields from QUIKRETE Concrete Mix.

23 posts, 63 rails and 319 boards for 146 feet of fence with 1 gate; 53 bags of 80-pound concrete (1.38 cubic feet per post).

How it's calculated

  • Fence length = total length − gates × gate width
  • Sections = fence length ÷ post spacing, rounded up, + 1 per corner
  • Posts = sections + gates + 1
  • Rails = sections × rails per section
  • Boards = fence length × 12 ÷ (board width + gap), rounded up; panels = sections
  • Concrete per post (cu ft) = (π × (hole diameter ÷ 2)² − post width²) × depth, in inches, ÷ 1,728
  • Bags = posts × concrete per post ÷ bag yield, rounded up

How to use it

  1. 1Measure the run. Enter the total length of fence, including gate openings, and the number of corners.
  2. 2Add gates. Enter how many gates and how wide each opening is.
  3. 3Choose the style. Pick boards or pickets (set the board width and gap) or pre-built panels, and the number of rails per section.
  4. 4Size the post holes. Enter the post width, hole diameter and the depth of concrete; QUIKRETE recommends a hole three times the post width.
  5. 5Add prices. Enter your prices to see the material cost.

Worked example

150 ft of 6 ft privacy fence with one 4 ft gate and two corners, posts every 8 ft, 3 rails, 5.5 in boards butted tight, 4×4 posts (3.5 in) in 10.5 in holes with 32 in of concrete, and 80 lb bags.

  1. Fence length = 150 − 4 = 146 ft
  2. Sections = 146 ÷ 8 = 18.25 → 19, + 2 corners = 21
  3. Posts = 21 + 1 gate + 1 = 23; rails = 21 × 3 = 63
  4. Boards = 146 × 12 ÷ 5.5 = 318.5 → 319
  5. Concrete per post = (π × 5.25² − 3.5²) × 32 ÷ 1,728 = 1.38 cu ft (2.3 eighty-pound bags)
  6. Bags = 23 × 1.38 ÷ 0.60 = 52.8 → 53 eighty-pound bags

Order 23 posts, 63 rails, 319 boards and 53 eighty-pound bags of concrete, plus the gate hardware.

Sources

  1. QUIKRETE, Setting Posts (project instructions). Accessed 2026-11-03.

    The diameter of the post hole should be 3 times the post diameter. Hole depth should be 1/3 the overall post length, plus 6 in. for a gravel base. An 8 ft post for a 6 ft fence gives about 32 in. of concrete.

  2. QUIKRETE, Concrete Mix No. 1101 data sheet. Accessed 2026-11-03.

    Yield: a 40 lb bag makes about 0.30 cu ft, a 60 lb bag about 0.45 cu ft and an 80 lb bag about 0.60 cu ft (50 lb: 0.375; 90 lb: 0.675).

  3. Millard Lumber, Building Wood Fences. Accessed 2026-11-03.

    Space posts about 6 to 8 ft apart depending on fence type, terrain and wind; bury about 1/3 of each wood post's length. Decorative styles use top, center and bottom rails.

FAQ

Fence calculator questions

Have a question we didn't cover? Book a demo and ask a product specialist.

How far apart should fence posts be?

Usually 6 to 8 ft. Eight feet matches standard rail and panel lengths; go closer for heavy boards, tall fences or windy sites. Check panel width if you're using panels.

How many bags of concrete per fence post?

It depends on the hole. A 4×4 in a 10.5 in hole with 32 in of concrete takes about 1.38 cu ft, or 2.3 eighty-pound bags. A 12 in hole takes more. The calculator works it out from your hole size using QUIKRETE's bag yields.

How deep should fence post holes be?

QUIKRETE recommends a third of the post's total length plus 6 in for gravel. In cold climates, go below the frost line, and follow local code.

Two rails or three?

Short fences often get by with a top and bottom rail; taller privacy fences commonly add a center rail to stiffen the boards, as in the top, center and bottom rail designs in Millard Lumber's guide. Pick what your spec or local practice calls for.

Why add a section for each corner?

Runs rarely divide evenly by the post spacing, so each corner usually adds a short section and a post. If your corners land exactly on the spacing, set corners to 0.

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