Fence Calculator

Plan a fence: posts, panels or pickets and rails, gates, and the bags of concrete to set the posts, for any length in feet or metres.

A fence comes down to posts, the panels or rails and pickets between them, and the concrete to set the posts. Posts are one more than the number of bays in each run, plus one for each gate. A 100 ft fence with a 4 ft gate and posts every 8 ft has 12 bays and 14 posts. With 3½ in pickets and 2½ in gaps it takes 184 pickets and 24 rails, and setting the posts in 10 in holes 2 ft deep takes about 24 × 80 lb bags of concrete. Switch to panels for the UK's 6 ft (1.83 m) panels, or enter your own spacing, and the calculator counts the posts, panels or pickets, rails and concrete.

Units
Bag sizes
Fence
ft
ft
ft
in
in
in
in
in
Posts
14

12 bays

Pickets
184

3.5 in wide

Rails
24

2 per bay

Concrete
24 bags

80 lb bag (0.60 ft³)

How it was worked out
  1. Fenced length: 100 ft less 1 gate of 4 ft = 96 ft
  2. Bays: 96 ÷ 8 ft = 12, rounded up to 12
  3. Posts: 12 bays + 1 to end the run + 1 for the gate = 14
  4. Pickets: (96 ft − 14 posts × 3.5 in) ÷ (3.5 in + 2.5 in gap) = 184 pickets
  5. Rails: 12 bays × 2 = 24
  6. Concrete: 10 × 24 in holes less the post, × 14 posts + 10% = 24 bags of 80 lb premix

Gate posts are often bigger and set deeper than line posts. Check boundaries, height limits and any permit rules before you build.

Common use cases

  • Plan a new picket, privacy or paling fence
  • Count fence panels and posts for a garden boundary
  • Work out the concrete for every post
  • Price a fence before getting quotes

How to use

  1. Choose your units and country, and pickets or panels.
  2. Enter the total length, the number of separate runs, and any gates.
  3. Enter the post spacing (or panel width), post width and, for pickets, the picket width, gap and rails.
  4. Enter the post hole size and concrete depth, then read the posts, pickets or panels, rails and bags.

FAQ

How many fence posts do I need?

Divide the fenced length (without gates) by the post spacing and round up for the bays, then add one post to end each run and one per gate. 96 ft of fence at 8 ft spacing is 12 bays and 13 posts, plus one for a gate.

How far apart should fence posts be?

Commonly 6 to 8 ft in the US; UK fence panels are usually 6 ft (1.83 m) wide, so posts go at 1.83 m plus the post. Windy sites and tall fences need closer posts.

How many pickets do I need?

Take off the gates and the width of the posts, then divide by one picket plus its gap. The calculator rounds up; add a few for splits and offcuts.

Related tools

Results are estimates for planning and buying materials, worked out from the figures you enter and typical values (weights, coverage, sizes) that vary by product and supplier. They are not engineering, building or professional advice. Check your local building code, the product maker's instructions and your supplier's figures before you buy or build, and use a qualified professional for structural, electrical and gas work.