Fence Calculator

By Stephen Morrison, Editor Last reviewed October 30, 2026

Enter the length of your fence line, its height and any gates. You get posts, rails, pickets and bags of concrete for the post holes, all in one shopping list.

Your fence

Total length

Measure along the fence line

Height

Post spacing

6–8 ft is typical

Gates

Gate width

Corners

More options: pickets, rails, post holes, prices

Picket width

A 1×6 is 5½ in actual

Gap between pickets

0 for a privacy fence

Rails per sectionAuto: 2 up to 4 ft tall, 3 above

Extra pickets

Hole diameter

Hole depth

Auto: ⅓ of the height, at least 2 ft

Concrete bag

Post price

Picket price

Rail price

Bag price

You need

– posts

– sections over – ft of fence

Rails (2×4, – ft)–
Pickets–
Concrete, 80 lb bags–
Post hole depth– ft
Estimated cost–

Shopping list

Quick answer: a 100 ft, 6 ft tall wood fence with one 4 ft gate and posts every 8 ft needs 14 posts, 36 rails, about 220 pickets and 22 bags of 80 lb concrete.

How the calculator works

Fence: total length − gates × gate width
Sections: fence ÷ post spacing, rounded up
Posts: sections + 1 + one per gate + one per corner
Rails: sections × rails per section
Pickets: fence (in) ÷ (picket width + gap), plus extra
Concrete: π × (hole ÷ 2)² × depth − the post (3.5 × 3.5 in), per post

The count assumes posts are shared between sections, as on a normal run. If your fence has separate runs that don't connect, add one post per extra run.

Materials for common fence lengths

6 ft tall, posts every 8 ft, no gates, 5½ in pickets side by side, 10 in × 2 ft holes.

Length	Posts	Rails	Pickets	80 lb bags
50 ft	8	21	115	13
100 ft	14	39	230	22
150 ft	20	57	344	31
200 ft	26	75	459	40

Before you dig

Call 811 a few days ahead so utility lines are marked.
Check permits, setbacks and HOA rules. Height limits are common, especially in front yards.
Find your frost depth. In cold climates, posts set above the frost line can heave.
Set corner and gate posts first, then run a string line between them for the line posts.

Common questions

How far apart should fence posts be?

For wood and composite privacy fences, most posts are set 6 to 8 ft apart. This calculator defaults to 8 ft, the most common rail length. Use closer spacing for tall fences or windy sites.

How deep should fence post holes be?

At least one-third to one-half of the post’s height above ground, so 2 to 3 ft for a 6 ft fence. In cold climates, go below your local frost line, and check local code, which can require more.

How many bags of concrete per fence post?

A 10 in wide, 2 ft deep hole around a 4×4 post holds about 0.92 cu ft of concrete, which is 2 bags of 80 lb mix or 3 bags of 60 lb mix per post.

How many pickets for 100 feet of fence?

With 5½ in wide pickets set side by side, plus 5% for splits and bad boards, about 220 for 96 ft of fence (100 ft minus one 4 ft gate). Spaced pickets need fewer: add the gap under "More options".

How many rails per fence section?

Builders commonly use two rails per section on fences up to 4 ft tall and three on taller privacy fences, which is what this calculator assumes. Change it under "More options" if your design differs.

Do I need a permit or a survey?

Many towns require a permit for fences over a certain height, and HOAs often have their own rules. Call 811 before you dig so buried utility lines get marked, and confirm your property line.

Sources

Formulas and figures last checked against these sources onOctober 30, 2026. Spotted an error? Tell us and we'll fix it.

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