Fence calculator

Job sheet

Plumb fence job sheet

80 ft run, posts 8 ft apart.

  • Posts11One more post than the number of spaces.
  • 80 lb concrete bags2917.28 cu ft in the holes at 0.6 cu ft per QUIKRETE 1101 bag. No waste added.
Plumb fence job sheet
80 ft run, posts 8 ft apart.

Posts: 11 (One more post than the number of spaces.)
80 lb concrete bags: 29 (17.28 cu ft in the holes at 0.6 cu ft per QUIKRETE 1101 bag. No waste added.)

Posts and bags

Posts = spaces rounded up, plus the post you start on. Rails and pickets depend on the style. This sheet does not invent a picket width. Measure one bay and multiply by the spaces (posts minus one).

Bags use the cylinder volume and 0.60 cubic feet per 80 lb bag. No waste is added here. If the auger wanders, add a percent on the concrete calculator or dig the hole you actually have. Yield tables for every bag size are on bags in a yard.

FAQ

How many posts?

Divide the run by the spacing and round up, then add one post for the start. An 80 foot run at 8 foot spacing is 10 spaces and 11 posts.

How many bags of concrete for a fence post?

One hole, 12 inches across and 24 inches deep, is about 1.57 cubic feet. QUIKRETE 80 lb bags yield 0.60 cubic feet, so that hole is 3 bags before waste. Eleven holes are the number on the sheet. A wider hole needs more. The concrete page adds a waste allowance if the dirt is rough.

Sources

  1. QUIKRETE Concrete Mix 1101: 80 lb bag yields 0.60 cu ft. The sheet also says a post hole about 3 times the post diameter and about one-third the post height.