Planning Your Fence Materials

Getting post count right is the foundation of a fence estimate — too few posts and the fence sags over time; too many wastes money and labor. This calculator works from your total fence length and post spacing to the exact post, rail, and concrete count.

The Formula

You always need one more post than the number of sections — think of a fence with 3 sections needing 4 posts (one at each end, two in between).

How to Use This Calculator

Measure your total fence run in feet. Set your post spacing — 8 ft on-center is standard for most wood and vinyl privacy fencing, though some styles use 6 ft for extra rigidity. Set rails per section based on your fence height (taller privacy fences typically use 3 rails; shorter picket fences often need only 2).

Concrete for Post Holes

A standard 4x4 wood post set in a hole roughly 24 inches deep and 10 inches in diameter typically takes about 2 bags of 50lb quick-setting concrete. Larger posts, deeper holes (recommended in colder climates to get below the frost line), or wider holes need more — adjust the bags-per-post input to match your local frost depth requirements and post size.

Corner and Gate Posts Need Extra Strength

Corner posts and gate posts bear more load than standard line posts and often need to be larger diameter or set in more concrete than a typical mid-run post. This calculator gives a uniform estimate — budget a bit extra for these higher-stress points.

Worked Example

A 150 ft fence line at 8 ft post spacing needs about 19 sections, requiring 20 posts and (at 3 rails per section) 57 rails. At 2 bags of concrete per post, that's 40 bags total.

Where This Fits Your Project

Pair this with our concrete calculator for larger pours, or our paint calculator if you're staining or painting the finished fence.

Frequently Asked Questions