Fence Calculator
Calculate posts, rails, and pickets needed for your fence. Get accurate material estimates for any fence project.
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Fence Building Guide
Picket count assumes 6-inch wide pickets with a 2-inch gap (approximately 5.5 pickets per linear foot). Set posts in concrete for maximum stability.
- Set posts in concrete: one 60lb bag per post hole
- Standard post depth: 1/3 of post length below ground
- Check local building codes for height restrictions
How to Calculate It Yourself
If you prefer to check the math by hand, follow these steps:
- Posts = (fence length / post spacing) + 1.
- Sections = number of posts - 1.
- Rails = sections x rails-per-section (2 or 3).
- Pickets ≈ fence length x 5.5 per linear ft.
Worked Example
A 100 ft fence at 8 ft spacing needs 13.5 posts, so 14 posts, 13 sections, 26 rails (2 rails each), and about 550 pickets.
Approximate Material Costs
Prices vary by region and supplier. These are rough US averages to help with budgeting.
| Item | Estimate | Notes |
|---|---|---|
| 4x4 post (8 ft) | $8 - $15 each | Pressure-treated |
| 2x4 rail (12 ft) | $6 - $10 each | Horizontal support |
| Picket (5.5 in x 48 in) | $2 - $4 each | Dog-ear style |
| Concrete per post | $4 - $6 | One 60 lb bag each |
Frequently Asked Questions
How many fence posts do I need?
Divide the total fence length by the post spacing, then add one for the starting post. For a 100-foot fence with 8-foot spacing, you need 14 posts.
How deep should fence posts be?
Fence posts should be buried at least 1/3 of their total length. For a 6-foot fence, use 8-foot posts with 2 feet in the ground. This provides adequate stability.
What type of wood is best for fence posts?
Pressure-treated pine is the most common and cost-effective choice. Cedar is naturally rot-resistant and looks great but costs more. Douglas fir is another strong option.
How much concrete do I need per fence post?
One 60lb bag of concrete mix per post hole is typically sufficient. Mix the concrete with water directly in the hole for the strongest bond.