Fence Calculator
Estimate posts, rails, pickets and concrete bags for wood, vinyl or privacy fences.
Last updated: September 2026 · Material-count math reviewed (not a structural, wind-load, or permit design service)
Best for a single straight or looped run with steady post spacing. Enter total gate width so pickets exclude openings. This tool estimates posts, rails, pickets, and concrete bags — not corner-post engineering, slope layout, or HOA/permit approval. Confirm post depth and height limits with local code.
Adds 2 posts per gate to the post count.
Subtracts from picket length only — not from posts. Leave blank if no openings.
Quick Answer: Posts, Rails & Pickets Formula
Posts ≈ ceil(length ÷ spacing) + 1 + (gates × 2).
Rails ≈ sections × rails per section (then add waste %).
Pickets ≈ (length − total gate width) ÷ (picket width + gap), then add waste % and round up.
Concrete bags ≈ posts × bags per post (planning estimate).
- Common post spacing: 6–8 ft (closer in high wind)
- Each gate usually needs two posts
- Subtract gate openings from the picket run so you do not order face material for the hole
How to Use This Fence Calculator
- Enter the total fence length (around the yard or along one side)
- Set post spacing (usually 6–8 ft)
- Add number of gates (extra posts are added automatically)
- Optionally enter total gate width so pickets and rails exclude openings
- Choose rails per section and optional picket width / gap
- Adjust concrete bags per post and waste, then calculate
How Many Fence Posts & Pickets? (Examples)
Quick reference for popular residential fence lengths. Includes 10% waste on rails and pickets, ~1.5 concrete bags per post, and 0.5" gap between pickets. No gates.
| Fence Length | Posts | Rails | Pickets | Concrete Bags |
|---|---|---|---|---|
| 50 ft | 8 | 16 | ~110 | ~12 |
| 75 ft | 11 | 22 | ~165 | ~17 |
| 100 ft | 14 | 29 | ~220 | ~21 |
| 150 ft | 20 | 42 | ~330 | ~30 |
| 200 ft | 26 | 55 | ~440 | ~39 |
Add 2 posts per gate. Always re-calculate with your exact length, spacing and picket size.
6 ft spacing contrast: A 100 ft run at 6 ft spacing needs more posts than at 8 ft (about 18 vs 14 before gates). Privacy boards with little or no gap also need more face boards than a 5.5" picket with 0.5" gaps — change picket width and gap in the calculator.
Typical Post Spacing
| Fence Type | Common Spacing |
|---|---|
| Wood privacy | 6 – 8 ft |
| Picket fence | 6 – 8 ft |
| Vinyl | 6 – 8 ft |
| High-wind areas | 4 – 6 ft |
| Chain-link | 8 – 10 ft |
Common fence heights
| Above-ground height | Typical use | Post length (rough) |
|---|---|---|
| 4 ft | Decorative / pet | ~6–7 ft post |
| 6 ft | Privacy (most common) | ~8–9 ft post |
| 8 ft | Extra privacy (where allowed) | ~10–12 ft post |
Post length ≈ above-ground height + embedment. Confirm HOA and local height limits before ordering tall panels.
Post hole depth (planning guide)
| Fence height | Common minimum depth |
|---|---|
| 4 ft | ~1.5–2 ft |
| 6 ft | ~2 ft (or ~⅓ of post above grade) |
| 8 ft | ~2.5–3 ft+ |
| Frost areas | Below local frost line |
Gate, corner, and end posts often need deeper or larger footings. For hole volume in cubic yards, use the concrete calculator with diameter × depth; bag counts above remain a simple posts × bags-per-post estimate.
Formulas Used
Sections = ceil(Fence length ÷ Post spacing)
Posts = Sections + 1 + (Gates × 2) (end/line posts plus two posts per gate)
Material run length = max(0, Fence length − Total gate width) — used for pickets; rails still follow section count along the full layout
Rails = ceil(Sections × Rails per section × (1 + Waste%))
Pickets = ceil(Material run length ÷ (Picket width + Gap)), then × (1 + Waste%), rounded up
Concrete bags = ceil(Posts × Bags per post) — planning estimate only; actual need depends on hole diameter, depth, and bag yield
Worked Example (100 ft + 4 ft Gate)
Inputs: 100 ft total length, one 4 ft gate, 8 ft post spacing, 2 rails per section, 5.5″ pickets with 0.5″ gaps, 10% waste, ~1.5 bags per post.
- Picket-run length = 100 − 4 = 96 ft
- Effective picket coverage = 5.5 + 0.5 = 6 in = 0.5 ft
- Base pickets = 96 ÷ 0.5 = 192 → with 10% waste ≈ 212 pickets
- Sections ≈ ceil(100 ÷ 8) = 13 → 14 line/end posts + 2 gate posts = 16 posts
- Rails ≈ ceil(13 × 2 × 1.10) = 29
Enter total gate width in the calculator so picket counts exclude openings. Final post layout still depends on corners and how gate posts replace or add to line posts on site.
Fence Material Types
This calculator estimates posts, rails, pickets, and concrete for common residential layouts. Different fence styles use materials differently — use the notes below as planning guidance, not a single formula for every product.
Wood picket fence
Typical materials: posts, 2–3 rails per section, individual pickets, and concrete for post holes. Enter picket width and gap to estimate picket count. Leave total gate width filled in so openings are not counted as picket area.
Privacy fence
Usually solid boards or tight pickets with little or no gap. May need heavier posts, an extra rail, and deeper footings in windy areas. Treat board width like picket width (gap often near 0) for a rough board count.
Vinyl panel fence
Often sold as pre-made panels with matching posts and gates. Manufacturer spacing and post inserts control the layout more than a generic picket formula. Use this tool for a rough post/section count, then confirm panel width and hardware with the product guide.
Horizontal board fence
Boards run sideways between posts. Post spacing and stock board length matter more than vertical picket pitch. You may need closer posts or stronger posts for taller horizontal designs — verify span limits for your board thickness.
One formula does not fit every fence type. Always match post size, spacing, and fasteners to the material and local conditions.
Corners, Ends & Slopes
Corners and ends still need posts. The basic formula (sections + 1) covers end posts on a single run. On a full yard loop, shared corner posts mean you should not double-count the same post for two sides — measure each run, then reconcile corners on your sketch. Terminal and gate posts are often set deeper or in larger holes than line posts.
Slopes: This calculator assumes a level run. On a grade, builders either step the fence (level sections with stepped tops) or rack panels with the slope. Post spacing is measured along the ground; panel and picket cuts change. Re-check counts after you choose a step or rack method.
What This Calculator Does Not Account For
This tool is for material planning only. It does not account for:
- Rocky soil, slopes, or uneven ground
- Frost depth, high wind, or local footing rules
- HOA rules, permits, or property-line setbacks
- Underground utilities or drainage conditions
- Manufacturer-specific vinyl systems or special gate hardware
- Structural post sizing, wind load design, or engineering review
Always confirm post depth, spacing, and gate construction with local code and product instructions before buying or installing.
Fence Building Tips
- Dig post holes below the frost line in cold climates
- A common starting point is to embed about one-third of the above-ground post height (or at least 2 ft for a 6-ft fence), but this is not universal — gate, corner, and end posts may need deeper or larger footings. For hole volume in bulk, cross-check with the concrete calculator
- Use gravel at the bottom of holes for drainage — estimate base material with the gravel calculator
- Set corner and end posts first, then line posts
- Corners: A closed perimeter needs a post at every corner. Straight runs still use Sections + 1; for a full yard loop, measure total length including all sides.
- Measure on the ground: Slope and curves increase real length versus a straight tape between end points — measure along the actual fence line.
- Each gate usually needs two sturdy posts — enter the number of gates so they are included
- Check local codes for height limits, setbacks, and required post depth
Important: This calculator estimates materials only. It does not design structural post size, wind load, frost depth, or property-line setbacks. Confirm local codes and manufacturer specs before building.
Frequently Asked Questions
Related measurements
Post concrete volume and bags are included above; for slabs or larger footings use the concrete calculator. Base gravel under the fence line: gravel calculator. Property edge length: square footage calculator. Browse all construction calculators.