Fence Post Spacing Calculator

Calculate fence post count, spacing, and concrete per post. Enter fence length and desired spacing for accurate post and footing estimates.

Total Posts
15.00
2 corner + 11 line + 2 gate posts
Panels Needed
12.00
8 ft sections at 6 ft height
Concrete Bags (60 lb)
23.00
For setting posts in ground (2 ft depth recommended)
Total Hardware
78.00
Brackets, screws, caps, and fasteners
Total Project Cost
$1,290.60
Posts: $180.00 | Panels: $864.00 | Gates: $85.00
Cost per Linear Foot
$12.91
Total cost divided by fence length
Estimated Weight
1,710 lbs
Expected lifespan: 15 years
Cost Breakdown
Posts
$180.00
Panels
$864.00
Concrete
$126.50
Gates
$85.00
Hardware
$35.10
Post TypeCost EachConcreteWeightLifespan
Wood 4x4$12.001.5 bags18 lbs15 yrs
Wood 6x6$28.002 bags35 lbs20 yrs
Steel T-Post$8.000 bags6 lbs30 yrs
Aluminum$45.001.5 bags8 lbs40 yrs
Vinyl (5x5)$35.002 bags12 lbs25 yrs
Planning notes, formulas, and examples

About the Fence Post Spacing Calculator

Fence post spacing is the foundation of any fence project. Get it right, and your fence stands straight and strong for decades. Get it wrong, and you'll deal with sagging panels, leaning posts, and costly repairs.

This calculator determines the number of posts, adjusts spacing for equal bays, and estimates the concrete needed for each post hole. Standard fence post spacing is 6–8 feet on center, depending on fence height, wind exposure, and design. Each post typically needs a hole 10‒12 inches in diameter and 24‒36 inches deep, filled with quick-setting concrete.

Whether you're planning a new fence or replacing posts on an existing one, This calculator ensures even spacing and accurate material estimates.

When This Page Helps

Even post spacing is essential for a professional-looking fence. Simply dividing the length by the spacing leaves odd partial bays. This calculator adjusts for equal bay widths so every section looks uniform.

How to Use the Inputs

  1. Enter the total fence line length.
  2. Enter the desired post spacing (6–8 ft typical).
  3. Set the post hole diameter and depth.
  4. Review the number of posts needed.
  5. Check the adjusted equal-bay spacing.
  6. Calculate total concrete bags for footings.
Formula used
Posts = (Length ÷ Spacing) + 1 (rounded up) Adjusted Spacing = Length ÷ (Posts − 1) Concrete per Post = π × (Hole Radius)² × Depth

Example Calculation

Result: 14 posts / ~21 bags concrete

100 ft ÷ 8 = 12.5, round to 13 bays + 1 = 14 posts. Adjusted spacing: 100 ÷ 13 = 7.69 ft (equal bays). Each hole: π × 5² × 24 = 1,885 in³ = 0.04 yd³ ≈ 1.5 bags, total: 21 bags.

Tips & Best Practices

  • Use 8-ft spacing for fences up to 6 ft; 6-ft spacing for taller or wind-exposed fences.
  • Set corner and gate posts first, then fill in line posts evenly.
  • Use a string line between corner posts to keep everything aligned.
  • Post holes should be 3× the post width (12 in for 4×4 posts).
  • Set posts plumb (level in both directions) before concrete sets.
  • Quick-setting concrete saves time — you can attach rails in 30‒60 minutes.

Why Equal Spacing Matters

If you just set posts at exact 8-ft intervals on a 100-ft fence, the last bay will be 4 ft — half the width of every other section. This looks sloppy and wastes a panel. Adjusting all bays to an equal width (like 7.69 ft) creates a professional, balanced appearance.

Post Hole Best Practices

Dig holes 3× the post width and at least 24 inches deep. Taper the hole wider at the bottom for a bell shape that resists frost heaving. Place 3 inches of gravel at the bottom for drainage before setting the post.

Concrete Setting Techniques

For dry-pack (pour dry mix, add water): fill around the post in layers, wetting each 6-inch lift. For premixed: mix concrete in a wheelbarrow or mixing tub and pour around the post. Crown the concrete above grade to shed water away from the post.

Accounting for Gates and Corners

Gate openings interrupt the regular spacing. Set gate posts at the desired opening width, then space the remaining line posts equally on each side. Corner posts count as two endpoints — calculate each fence leg separately.

Sources & Methodology

Last updated:

Frequently Asked Questions

  • The standard is 8 feet on center for most residential fences using 4×4 posts and 2×4 rails. Wind-prone areas and tall fences (over 6 ft) should use 6-foot spacing for added strength.