Fence Calculator

A complete materials list for a post-and-rail picket or privacy fence — including the concrete for every post.

Updated September 2026 · Free, no sign-up · How it works

Layout
ft
Each run starts and ends with a post.
ft
8 ft is common; follow your design and local code.
ft
Materials
Often 3 for fences over about 6 ft.
in
A nominal 1×6 is 5.5 in actual.
in
0 for privacy.
in
A nominal 4×4 is 3.5 in.
in
in
Follow local frost-depth rules.

How the materials are counted

Fence length (excl. gates) = total length − gates × gate width Sections per run = ⌈run length ÷ post spacing⌉ Posts = sections + 1 per run + 1 per gate Rails = sections × rails per section Pickets = ⌈fence length × 12 ÷ (picket width + gap)⌉ Concrete per post = π × (hole Ø ÷ 2)² × depth − post width² × depth

Concrete bags use QUIKRETE’s published yields (0.375 cu ft per 50 lb bag, 0.60 cu ft per 80 lb bag). Lumber sizes are actual dimensions: a “4×4” post is 3.5 × 3.5 in and a “1×6” picket is 5.5 in wide.

Worked example

150 ft of fence on three sides with one 4 ft gate, posts every 8 ft, two rails, 5.5 in pickets with 0.5 in gaps, 10 × 30 in post holes:

Fence length excl. gate146 ft
Sections21
Posts25
Rails42
Pickets292
Concrete28.8 cu ft = 48 bags of 80 lb

Call 811 before you dig so underground utilities are marked, and check property lines, permits and HOA rules first.

Frequently asked questions

How far apart should fence posts be?

Eight feet on center is the most common spacing for wood fences, and many plans use 6 ft for taller or heavier fences. Follow your fence design and local code.

How many bags of concrete per fence post?

For a 10 in hole 30 in deep around a 4×4 post, about 1.15 cu ft: two 80 lb bags (0.60 cu ft each).

Sources

Reviewed and updated September 2026. Found an error? Tell us — we correct mistakes promptly. See our methodology.