Fence Calculator for Posts, Panels, Spacing & Cost

How to Calculate Fence Materials

1. Calculate posts

Divide total length by post spacing and round up to get the number of sections. Posts equal sections plus one, plus any extra posts required at corners or gates.

2. Calculate rails

Most wood and metal fences use two or three horizontal rails per section. Chain-link fences typically use a top rail plus bottom tension wire. Vinyl privacy fences commonly use two rails per section.

3. Calculate pickets or panels

For picket fences, divide the length of each section by (picket width + gap). Privacy and vinyl fences are often sold as full panels sized to the chosen spacing.

4. Calculate concrete

Each post sits in a hole. Hole diameter is roughly three times the post width. Hole depth is about one-third of the above-ground height plus 6 inches. Concrete volume equals hole volume minus the volume of the embedded post. Results are shown for both 60 lb and 80 lb bags.

Fence Post Spacing and Depth

6 ft spacing is used where wind loads are high or the fence is tall. 8 ft is the most common spacing for residential wood privacy fences. 10 ft spacing can be used with lighter materials if the posts and rails are strong enough. A frequent rule of thumb is to bury one-third of the post length. In areas with frost, the bottom of the post should extend below the local frost line. Local building departments publish the exact frost depth and any required embedment.

Material List for a Typical Fence

Example quantities for a 100 ft fence. All numbers are placeholders pending verification against common product sizes.

Fence Cost by Material

Material-only cost ranges per linear foot. Labor, gates, and site conditions are excluded. All figures are placeholders.

Before You Dig: Permits, Property Lines and Utilities

Call 811 before any excavation so underground utilities can be marked. Confirm property lines with a survey or existing records. Check with your local building department and homeowners association for height limits, setback requirements, and permit rules. Regulations differ by jurisdiction; do not rely on general guidance alone.

FAQ

What is a typical fence post spacing?

Most wood privacy fences use 8 ft spacing. 6 ft is used for heavier loads or high wind areas. 10 ft is sometimes used with lighter materials or additional bracing.

How many posts do I need for 100 ft of fence?

At 8 ft spacing, 100 ft requires approximately 14 posts (sections + 1). Exact count depends on gates, corners, and chosen spacing.

How much does 100 ft of fence cost?

Cost varies widely by material, region, and labor. Material-only estimates range depending on wood, vinyl, or chain link. Always check local supplier pricing.

How deep should fence posts be buried?

A common rule is to bury one-third of the post length. In frost-prone areas the bottom of the post should extend below the local frost line. Check local building codes for exact requirements.

Do I need a permit for a fence?

Requirements vary by city and HOA. Many areas require permits for fences above a certain height or near property lines. Contact your local building department and call 811 before digging.

Which fence material lasts the longest?

Vinyl and aluminum generally require less maintenance and last longer than untreated wood. Treated wood and chain link have intermediate lifespans. Actual longevity depends on climate, installation quality, and maintenance.

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