Fence Calculator

Estimate fence posts, rails, pickets, and post-hole concrete by entering fence length and height. Get a full material list for wood or vinyl.

Mason ReidFounder and Lead Estimator at MeasureThen

Last updated 2026-08-21

What Is a Fence Calculator?

The fence calculator builds a full material list for a wood or vinyl fence. Enter the fence length, height, and post spacing, and it returns the number of posts, rails, and pickets you need to order.

How It Works

Posts = ceil(Length ÷ Spacing) + 1. Rails = (Posts − 1) × 2 (or 3 for ≥5 ft). Pickets = ceil(Length × 12 ÷ 6).

Example

A 100 ft fence at 8 ft spacing: 14 posts, 13 sections → 39 rails at 6 ft height, 200 pickets.

How to Calculate

Measure the total length of the fence line in feet. A 100 ft fence is a good starting point.
Choose a post spacing, typically 8 ft on center for a standard wood fence.
Enter the length, height, and spacing. At 100 ft and 8 ft spacing you get 14 posts and 13 sections.
Read the rail count. A 6 ft fence needs 3 rails per section, so 13 sections call for 39 rails.
Check the picket count. At about 2 pickets per foot, a 100 ft fence needs roughly 200 pickets, then add extra for gates and waste.

Standard Fence Post Spacing by Height

Fence Height	Post Spacing	Posts per 100 ft	Rails per Section
3 ft	8 ft	14	2
4 ft	8 ft	14	2
5 ft	8 ft	14	2 or 3
6 ft	8 ft	14	3
6 ft	6 ft	18	3

Sources

Frequently Asked Questions

What spacing should posts have?

6–8 ft on center is standard for wood fences; wider spacing needs heavier rails.

How many pickets per foot?

At a 6 in pitch (5.5 in picket + 0.5 in gap), that is about 2 pickets per linear foot.

Do I need to account for gates?

Yes — each gate adds posts and extra hardware. Use the post calculator for gate impact.

Mason ReidFounder and Lead Estimator at MeasureThen

Mason Reid founded MeasureThen after two decades of hands-on work in construction and estimating. Across residential and light commercial projects, he sized concrete pours, framed walls, hung drywall, and priced out roofing, fencing, and deck work — learning the exact math that every job depends on. At MeasureThen he writes the formulas, checks every calculator against real-world assumptions, and makes sure each one is simple enough for a homeowner to trust and a contractor to use. When he is not measuring twice, he is helping projects stay on budget.

Every MeasureThen calculator uses simple, transparent formulas and standard industry assumptions drawn from common construction practice. We show the math behind each result and include worked examples so you can follow along and double-check the numbers. Results are estimates: materials, labor, and pricing vary by region and market, so always confirm important figures with a licensed professional and your local building codes.