Fence Calculator — How Much Fencing Do I Need?
Calculate how many posts, rails, and pickets you need for your fence project. Enter your fence length and style to get a complete materials list.
Materials You'll Need
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Simpson Strong-Tie Post Base (4x4, 10 pack)
Anchors fence posts to concrete footings — prevents rot at the base
QUIKRETE Fast-Setting Concrete Mix (50 lb bag)
Sets fence posts in 20-40 minutes — one bag per post hole is typical
Post Hole Digger (48 in handles)
Manual post hole digger for setting fence posts — essential for any fence project
Stainless Steel Fence Screws (1 lb box)
Rust-resistant screws for attaching pickets and rails — outlast standard screws
Assumptions
- One post at each end and every post-spacing interval along the fence line
- Gate posts are counted separately — add them to the fence post total
- Pickets are only counted for fence sections (gate openings are excluded)
- Rails span between every pair of adjacent posts
- Standard 4×4 posts for most wood fences; 6×6 for gate posts and corners recommended
- Posts should be set at least 2 feet deep (1/3 of total post length underground)
- Does not include corner posts or end posts separately — they are part of the total post count
Your Fence Project Guide
Building a fence is a serious DIY project, but it's absolutely doable with the right planning — and that starts with knowing exactly how many posts, rails, and pickets you need. This fence calculator takes your total fence length, style preferences, and gate requirements, then generates a complete materials list so you can price out your project accurately before you start digging.
Post spacing is the foundation of a sturdy fence. The standard 8-foot spacing works well for most 6-foot privacy fences using standard lumber. If you're building a taller fence (8 feet) or live in an area with high winds, consider tightening your post spacing to 6 feet for extra rigidity. Vinyl and composite fences often have specific post spacing requirements from the manufacturer — always check before you dig.
The most common beginner mistake is underestimating how much concrete you'll need for post holes. Each post should sit in a hole about 10 inches in diameter and at least 24 inches deep (or one-third of the total post length). A single 50-pound bag of fast-setting concrete is typically enough for one post. For a 100-foot fence with 14 posts, that's 14 bags — plus a few extra for gate posts, which should be set deeper and with more concrete since gates put extra stress on their posts.
Gate planning deserves special attention. Every gate needs two dedicated gate posts, and these should be 6x6 lumber (not 4x4) because they bear the weight of the swinging gate. A standard walk-through gate is 3 to 4 feet wide. If you need vehicle access, plan for a double gate that's 10 to 16 feet wide, which requires a center latch post in addition to the two hinge posts.
Before you buy a single board, check your local building codes and HOA rules. Many municipalities limit fence height to 6 feet in backyards and 4 feet in front yards. You'll also want to call 811 (the national utility locator) at least a few days before you dig — hitting a buried gas line or cable is dangerous and expensive.
For the lumber itself, pressure-treated pine is the most cost-effective choice for structural posts and rails. Cedar costs more but naturally resists rot and insects without chemical treatment, and it weathers to an attractive silver-gray over time. Whichever wood you choose, apply a water-repellent stain or sealant within the first year to maximize the life of your fence.
Frequently Asked Questions
How far apart should fence posts be?
Standard fence post spacing is 8 feet for most wood fences. For taller or heavier fences (6–8 ft), 6-foot spacing provides more stability. Vinyl and metal fences may allow up to 8–10 feet between posts.
How many fence posts do I need for 100 feet of fence?
With standard 8-foot post spacing, you need 14 posts for 100 feet of fence (100 ÷ 8 = 12.5, rounded up to 13, plus 1 for the end post). Add 2 extra posts for each gate opening.
How deep should fence posts be?
Fence posts should be buried at least 2 feet deep, or about 1/3 of the total post length. For a 6-foot fence, use 8-foot posts with 2 feet underground. In cold climates, set posts below the frost line.