Fence Calculator
Calculate fence materials needed for wood privacy, wood picket, or chain link fences.
Typical: 8 ft for wood fences, 10 ft for chain link
Each gate replaces one panel section
About This Calculator
This fence calculator helps you estimate the materials needed to build a wood privacy fence, wood picket fence, or chain link fence. Enter your total fence length, height, post spacing, and number of gates to get a complete materials list including posts, rails, pickets or mesh, concrete, and hardware.
Post depth and sizing: A general rule of thumb is to bury one-third of the total post length underground. For a 6-foot fence, use 9-foot posts with 3 feet buried. Posts should be set in concrete for stability - plan on two 60-pound bags of concrete per post. Dig post holes approximately 10 inches in diameter and deep enough so the post sits on 4-6 inches of gravel for drainage before the concrete is poured.
Concrete setting: Fast-setting concrete can be poured dry into the hole and then soaked with water, or mixed in a wheelbarrow and poured around the post. Allow at least 24-48 hours for the concrete to cure before attaching rails and pickets. In cold weather, curing may take longer. Crown the concrete slightly above ground level so water runs away from the post base.
Wood fence types: Privacy fences use 5.5-inch wide pickets placed edge to edge with no gaps, providing complete visual screening. Picket fences use 3.5-inch wide pickets spaced approximately 1.75 inches apart for a classic look. Fences under 6 feet tall typically need two horizontal rails, while fences 6 feet and taller require three rails for adequate support and to prevent warping.
Chain link fences: Chain link uses terminal (end/corner/gate) posts and line posts. Top rail is sold in 10.5-foot sections that sleeve together. Tension bars and bands are needed at each terminal post to stretch the mesh fabric taut. Chain link is generally the most economical fencing option and requires less maintenance than wood, though it offers less privacy unless slats or screening are added.
Last updated: April 21, 2026· Reviewed by the CalcNeeds Team
About This Calculator
This fence calculator estimates the number of posts, rails, pickets, and concrete bags you need for a new fence. Enter the total linear footage, choose your fence style — wood privacy, wood picket, or chain link — and the tool returns a complete materials list. It accounts for post spacing, gate openings, and the extra terminal posts required at corners and ends.
Whether you are building a backyard privacy fence or enclosing a property line, knowing your material quantities before you visit the lumberyard prevents costly over-orders and frustrating return trips. The calculator uses standard industry spacing rules so the results match what a professional installer would quote.
For irregularly shaped yards, measure each straight run separately and add the totals. Remember that each direction change requires an additional corner post, which this calculator factors in automatically when you specify the number of corners.
How many fence posts do I need?
The number of posts depends on total fence length and the spacing between posts. The standard spacing for wood fences is 8 feet on center, though 6-foot spacing is common for areas with high winds or heavy privacy panels. To calculate: divide the total fence length by the post spacing and add one for the starting post. A 100-foot fence at 8-foot spacing needs 100 / 8 + 1 = 14 posts.
Corner posts, end posts, and gate posts are additional. Each gate opening requires two gate posts, which are often larger (e.g., 6x6 instead of 4x4) to handle the extra stress of a swinging gate. Always count these separately and size them up from your line posts.
Post spacing, rails, and picket counts
Rails run horizontally between posts and support the pickets or panels. A standard 6-foot-tall privacy fence uses three rails per bay — top, middle, and bottom. Shorter fences (4 feet or under) typically need only two rails. Each bay between two posts requires its own set of rails, so a 100-foot fence with 8-foot spacing has 13 bays and needs 39 rails for a three-rail design.
Pickets attach vertically to the rails. A standard dog-ear picket is 5.5 inches wide with a 0.25-inch gap between boards. That works out to roughly 17 pickets per 8-foot bay or about 2.1 pickets per linear foot. For a 100-foot fence, expect to need around 210 pickets, plus 5-10% extra for waste and cuts.
Chain link fences use different terminology — line posts every 10 feet, top rail sold in 21-foot lengths, and fabric sold by the roll (typically 50 feet). The calculator adjusts all quantities automatically based on the style you select.
Concrete and setting fence posts
Each fence post needs to be set in concrete for stability. The general rule is to bury one-third of the total post length below ground. For a 6-foot fence with 8-foot posts, that means a 24-inch-deep hole. Most professionals dig holes 10-12 inches in diameter using a post-hole digger or power auger.
A standard 10-inch-diameter, 24-inch-deep post hole requires about one 50-lb bag of pre-mixed concrete (or two-thirds of an 80-lb bag). For a 100-foot fence with 14 posts, plan on 14 bags of concrete. In wet or sandy soils, increase the hole diameter to 12 inches and use 1.5 bags per post for added stability.
Fast-setting concrete is popular for fence posts because it can be poured dry into the hole and then soaked with water — no mixing required. Posts are typically firm enough to attach rails within 4 hours and fully cured within 24 hours.
Wood vs. vinyl vs. chain link fencing
Wood (cedar or pressure-treated pine) is the most popular residential fencing material. Cedar costs $15-$25 per linear foot installed and lasts 15-20 years with maintenance. Pressure-treated pine is cheaper ($10-$18/ft) but requires staining or sealing every 2-3 years.
Vinyl (PVC) fencing costs $20-$40 per linear foot installed but requires almost no maintenance and can last 30+ years. It will not rot, warp, or need painting. However, it has a limited color selection and can crack in extreme cold.
Chain link is the most economical option at $8-$15 per linear foot installed. It provides boundary definition and security without blocking views or airflow. Adding privacy slats or fabric brings the cost closer to wood while adding partial screening.
Fence height regulations and permits
Most municipalities limit backyard fences to 6 feet and front-yard fences to 4 feet. Corner lots may have additional sight-line restrictions within a certain distance of the intersection. Before building, check your local zoning ordinance and HOA rules — a fence built in violation can result in a forced teardown.
Many areas require a building permit for fences over 6 feet tall, and some require permits for any new fence regardless of height. The permit process typically costs $20-$75 and may require a site plan showing the fence location relative to property lines. Fences are usually required to be set 2-6 inches inside your property line, not directly on it.
Frequently Asked Questions
How many fence posts do I need for 100 feet of fence?
With standard 8-foot spacing, you need 14 posts (100 / 8 + 1 = 13.5, rounded up to 14). With 6-foot spacing, you need 18 posts. Add extra posts for each corner and each side of a gate opening.
How far apart should fence posts be?
Standard post spacing is 8 feet on center for wood fences and 10 feet for chain link. In high-wind areas or for heavy panel fences, reduce wood fence spacing to 6 feet. Never exceed 8 feet for wood fences — the rails will sag and the fence will lean over time.
How many bags of concrete do I need per fence post?
One 50-lb bag of fast-setting concrete per post for a standard 10-inch-diameter, 24-inch-deep hole. For larger 12-inch holes or deeper settings, use 1.5 to 2 bags per post. An 80-lb bag covers about 1.5 standard post holes.
How many pickets do I need for a fence?
About 2.1 standard pickets (5.5 inches wide with 0.25-inch gaps) per linear foot. For a 100-foot fence, that is roughly 210 pickets. Add 5-10% extra for waste, cuts, and replacements. Privacy fences with no gaps use about 2.2 pickets per foot.
How deep should fence posts be buried?
Bury one-third of the total post length. For a 6-foot-tall fence using 8-foot posts, set them 24 inches deep. In frost-prone areas, the bottom of the post should ideally reach below the frost line — typically 36 inches or deeper in northern states.
How much does it cost to build a fence per foot?
Wood privacy fencing costs $15-$25 per linear foot installed. Vinyl runs $20-$40 per foot. Chain link is the cheapest at $8-$15 per foot. A typical 150-foot backyard fence costs $1,500-$4,000 for wood, $3,000-$6,000 for vinyl, or $1,200-$2,250 for chain link.
How many rails do I need for a 6-foot privacy fence?
Three horizontal rails per bay — top, middle, and bottom. With 8-foot post spacing, each bay needs three rails. A 100-foot fence has about 13 bays, so you need 39 rails. Rails are typically 2x4 lumber cut to match the post spacing.
Do I need a permit to build a fence?
It depends on your municipality. Many cities require permits for fences over 6 feet tall, and some require permits for any new fence. Check your local zoning office before building. Fences typically must be set 2-6 inches inside your property line, not on the boundary itself.
How long does a wood fence last?
A cedar fence lasts 15-20 years with regular maintenance (staining or sealing every 2-3 years). Pressure-treated pine lasts 15-20 years as well but needs more frequent sealing. Without maintenance, expect 8-12 years before significant rot and leaning occur.
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