PLANKMATH

Fence

One measurement — the run — becomes the whole lumber list: posts, rails, and the picket count your gaps decide.

The run
Pickets — on the counter

Your buy list

0

pickets · 0 posts · 0 rails
Sections
Post depth
Concrete bags

Count gates separately — hardware, hinges, and a stiffer frame.


From one tape walk to a truck load

Walk the run once and the rest is arithmetic with opinions. Posts divide the line into sections — every section needs three rails on a privacy fence, and the line always ends with one more post than it has sections. Pickets march down the run at face-width plus gap, so the gap you choose for looks decides the lumber count directly.

Concrete is the hidden line item: each post hole wants about half a bag for a 6-foot fence, a full bag where frost digs deep. The estimate above uses half a bag per post.

Corner posts are different posts

Corners and gate posts carry pull from two or more directions — use 4×4 or 6×6 there even if the line runs 4×4, and set them deeper than the field posts.


On the counter

The assumptions this calculator ships with — every one is adjustable in the form.

Post spacing
8 feet on center — adjust for wind exposure
Rails
Three per section (6 ft privacy standard)
Pickets
5.5" face with 1.75" gaps — both adjustable

Questions from the aisle

How far apart should fence posts be?

6 to 8 feet for wood privacy fencing — 8 is the common default and what this calculator assumes. Shorter spans stiffen the run against wind and sagging gates.

How many pickets for 100 feet of fence?

With 5.5-inch pickets and 1.75-inch gaps, about 205 pickets. Tighten the gap and the count climbs; the calculator tracks it live as you adjust.

How deep do posts go?

One-third of the fence height, minimum 2 feet, and below the frost line where ground freezes. A 6-foot fence wants 8-foot posts set 2.5–3 feet deep.

How many rails per section?

Two for short decorative runs, three for 6-foot privacy fences — top, bottom, and center. The rail count above assumes three; halve it for a two-rail design.



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