Fence post depth scales roughly with height — a third of what's above ground needs to go below it — but frost depth often overrides that in cold climates. This chart covers every common fence height from 3 to 10 feet, shows total post length needed, and explains how to adjust the numbers for your local climate.
Fast-setting concrete is the easiest choice for a handful of posts, but its per-bag premium adds up fast across a full fence line — where standard mix saves real money for a little extra effort. This guide compares all three main mix types by strength, set time, and cost at scale, plus when gravel or foam makes sense instead of concrete.
Home>Concrete>Round vs Square Fence Post Holes Round vs Square Fence Post Holes: How Concrete Volume Changes A “12-inch hole” isn’t one number — a 12-inch round hole and a 12-inch square hole hold noticeably different amounts of concrete, even though…
A gate post resists real leverage a standard fence post never sees, which is why it needs a bigger post, wider hole, and more concrete. This guide breaks down concrete needs by gate weight class, covers hinge vs. latch post sizing and post spacing math, and walks through worked examples from a light garden gate to a heavy driveway gate.
Ten standard 4x4 fence posts need about 20 bags of 80 lb concrete — but gate and corner posts, bag size choice, and total weight all shift that number in practice. This guide gives full totals by post size, shows how to handle a mixed batch of line and corner posts, and compares bag sizes on total count and weight.
Fence posts rarely fail from bad math — they fail from small mistakes before, during, or after the pour. This guide covers the full list grouped by stage, including the genuine industry debate over whether concrete causes post rot, and how a post base bracket can sidestep the question entirely.
Most leaning fence posts fail for the same reason: plumb only got checked on one side. This step-by-step guide covers the full process — digging, gravel base, bracing on two adjacent sides, the plumb check that actually matters, pouring, crowning the top, and exactly how long to leave the bracing on before it's safe to build on.
The standard rule is 3 times the post's width, but post hole diggers and augers only come in fixed sizes — 9 and 12 inches are the two most common for a 4x4 post. This guide explains the reasoning behind the 3x rule, matches it to real available tool sizes, and shows how much adjustment "wiggle room" each hole diameter actually provides.
An 8 ft fence post needs more than a scaled-up version of a 6 ft post's numbers — wind load and deeper holes both come into play. This guide covers 4x4 vs. 6x6 sizing, depth by wind exposure and climate, the post-length availability issue tall fences run into, and full bag-count worked examples.
One page with every fence post concrete number you need — hole diameter by post size, depth by fence height and climate, bag yield by size, complete bag-count matrices for 4x4 and 6x6 posts, and total bags for a full fence line by spacing. Find your row, read across.