Fence Calculator

How to Use the Fence Calculator

Select your fence style, enter the total fence length, height, and post spacing. For picket or privacy fences, specify board width and gap. For panel fences, enter the panel width. The calculator automatically determines posts, rails, boards, concrete, and hardware quantities.

Fence Styles Explained

Privacy Fence

Privacy fences feature vertical boards installed side-by-side with no gaps, providing complete visual screening. Standard height is 6 feet with boards typically 5.5 or 3.5 inches wide. Requires 3 horizontal rails for support.

Picket Fence

Classic picket fences have pointed or flat-topped vertical boards with gaps between them. Usually 3-4 feet tall, they define boundaries while maintaining visibility. Spacing between pickets is typically 1.5-2 inches.

Post and Rail Fence

Also called split rail or ranch fencing, this style uses only horizontal rails between posts. Common for property boundaries, livestock areas, or decorative purposes. Typically 3-4 feet tall with 2-3 rails.

Panel Fence

Pre-assembled fence panels (usually 6 or 8 feet wide) install between posts. Faster to install than board-by-board construction. Common for privacy and dog-ear style fences.

Standard Fence Specifications

Post Installation Guidelines

• Depth: Set posts 1/3 of total post length in the ground (minimum 2 feet for 6-foot fence)
• Hole diameter: 3 times the post width (10-12 inches for 4x4 posts)
• Gravel base: Add 4-6 inches of gravel at bottom for drainage
• Concrete: Use quick-setting concrete for stability; 2-3 bags per post
• Check level: Ensure posts are plumb before concrete sets

Material Ordering Tips

• Order 10-15% extra materials for cuts, waste, and future repairs
• Choose pressure-treated lumber for ground contact and weather resistance
• Use galvanized or stainless steel fasteners to prevent rust
• Consider local building codes and HOA requirements before purchasing
• Call 811 before digging to locate underground utilities

Frequently Asked Questions

Is 6 ft or 8 ft post spacing cheaper?

Wider spacing needs fewer posts, holes and bags of concrete, so 8 ft spacing is usually cheaper in materials and labor. The trade-off is a longer rail span that sags or flexes more, which is why 6 ft spacing is common for tall privacy fences and in windy areas. The calculator shows both side by side for your fence.

Can I use my own material prices?

Yes. Open Your Prices and enter what your local store charges per post, rail, picket, panel, bag of concrete and gate kit, in any currency. The cost breakdown, the cost per foot and the post spacing comparison all use your prices; anything left blank uses a typical US price.

How many fence posts do I need?

The number of fence posts depends on your total fence length and post spacing. Typically, posts are spaced 6-8 feet apart. Divide the fence length by the post spacing, round up to get the sections, then add 1. For example, a 100-foot fence with 8-foot spacing has 13 sections (100/8 = 12.5, rounded up) and needs 14 posts. Each gate adds one more post, because the opening splits the run; the posts on either side of it are the gate posts.

How deep should fence posts be set?

Fence posts should be buried at least 1/3 of their total length. For a 6-foot fence, posts should be at least 2 feet deep, making the total post length 8 feet. In areas with frost, posts should extend below the frost line (typically 36-48 inches). Always add 4-6 inches of gravel at the bottom for drainage.

How many bags of concrete per fence post?

For a standard 4x4 post in a 10-inch diameter hole that is 2 feet deep, you will need 2-3 bags of 50-lb quick-setting concrete per post. Deeper holes or larger posts require more concrete. A 3-foot deep hole typically needs 3-4 bags per post.

What is the standard spacing between fence pickets?

For privacy fences, pickets are installed with no gap (0 inches) for complete coverage. Picket fences typically have 1.5-2 inch gaps between boards for the classic look. Shadow box fences alternate pickets on each side with about 1-inch overlap.

How much does it cost to build a fence?

Materials for a wood privacy fence typically cost $12-25 per linear foot. A 100-foot fence might cost $1,500-2,500 in materials. Labor adds $15-35 per linear foot if hiring a contractor. Panel fences and chain link are generally less expensive, while cedar and composite materials cost more.

How many 5.5-inch boards do I need for 100 feet of solid privacy fence?

For a straight 100-foot run with boards installed edge to edge, divide 1,200 inches by 5.5 inches per board. That gives about 219 boards per row, rounded up. Multiply by the fence height in boards; for a 6-foot fence using 6-foot boards, that is about 1,314 boards before waste. Add extra for cuts and damaged boards, and account separately for gates and any layout changes.

How should I account for a sloped yard when estimating fence materials?

Measure the fence along the planned line and decide whether the fence will follow the ground or use level steps between posts. A sloped run can change the needed board lengths, panel layout, and clearance under the fence, so a simple length-and-height estimate may not capture every cut. For example, if a 20-foot section rises 2 feet, plan the post and board layout around that rise before ordering materials.

Does a gate width count as part of the fence length?

Measure the total boundary run, including the opening where the gate will go, then subtract the gate opening when estimating rails, boards, or panels that do not cross it. For example, a 40-foot run with a 4-foot gate has 36 feet of fence material along that line. The gate needs its own gate kit and support posts; the calculator’s gate fields help include the gate and its posts.