fence project guide

How Many Fence Posts for 100 Feet?

For a straight 100-foot fence run, you need about 14 posts at 8-foot spacing or 18 posts at 6-foot spacing before adding special gate or corner posts.

Quick answer
About 14 posts at 8-foot spacing; about 18 posts at 6-foot spacing for a straight run.

How the estimate works

The useful way to estimate this project is to start from the actual dimensions, convert them into the correct volume or coverage units, and then apply a realistic planning allowance. PrepMyBuild keeps the assumptions visible so you can change them instead of relying on a black-box estimate.

ceil(total length ÷ spacing) + 1
6 ft18 posts~17 sections
8 ft14 posts~13 sections
10 ft11 posts~10 sections
Run your own dimensions

Use the calculator with your actual project measurements instead of relying on this example alone.

Use the fence calculator →

What can change the result?

Planning estimate only. Verify field conditions, product specifications, local requirements and contractor/supplier assumptions before purchasing materials.

Using this when reviewing a contractor quote

Compare the quote’s dimensions and stated scope with your own measurements. If the contractor’s quantity differs, ask what is driving the difference: thickness, waste, extra areas, compaction, openings, gate posts, surface condition or another project-specific assumption.

The goal is not to label a quote high or low from one calculation. The goal is to understand whether the scope and assumptions are clear enough for you to compare proposals confidently.

Frequently asked questions

Is this an exact ordering quantity?

No. It is a planning estimate based on the stated dimensions and assumptions. Field conditions, supplier increments, compaction, waste and project details can change the final order.

Can I use this to check a contractor quote?

Yes. Use the quantity as a reasonableness check, then compare the contractor’s stated dimensions, thickness, materials and scope rather than judging the quote on one number alone.

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