How deep should fence posts be?

One-third of the post height below grade — typically 24–36 inches for a 6-ft fence, below the local frost line.

Fence Calculator

Calculate posts, rails, and pickets for any linear fence. Defaults to 8-ft post spacing and a standard 6-ft privacy fence.

Inputs

Total length(ft)

Post spacing

Rails per section

Picket width(in)

Gap between pickets(in)

Price per linear ft (optional)($)

Result

Posts

Rails

200 ft

Pickets

200

Linear length: 100 ft
Post spacing: 8 ft

Diagram

Estimates only. Verify with a licensed contractor or supplier before purchasing. Rough Estimator! is not responsible for shortages, overages, or material variances. See our methodology for formulas and sources.

Formula

Posts = ceil(length ÷ spacing) + 1   ·   Pickets = ceil(length ÷ ((picketW + gap) ÷ 12))

Related tools & materials

Calculators

Don't forget

Post-hole concrete
Galvanized screws
Stain

Frequently asked questions

With 8-ft spacing you need 13 posts (12 sections + 1 closing post).

Cite this page

Cosyslabs. (2026). Fence Calculator. Rough Estimator!. https://roughestimator.com/fence-calculator

Embed on your site

Free for any site — attribution appreciated.

<iframe src="https://roughestimator.com/fence-calculator?embed=1" title="Fence Calculator" width="100%" height="640" style="border:0;border-radius:12px" loading="lazy"></iframe>