Inputs
Units: Imperial (feet)
ft
Straight run only. For corners, calculate each run separately.
ft
ft
ft
ft
ft
Gate openings are subtracted from total run. Positions assume a continuous run.
Results
| # | Position (run unit) | Position (alt unit) | Next bay length |
|---|---|---|---|
| No results yet. Enter inputs and click Calculate. | |||
Example Data
| Units | Total length | Mode | Value | Include ends | Equalize | Gates | Setbacks | |
|---|---|---|---|---|---|---|---|---|
| Imperial | 100 ft | Spacing | 8 ft | Yes | Yes | 0 | 0/0 ft | |
| Metric | 30 m | Panel | 2.4 m | Yes | Yes | 0 | 0/0 m | |
| Imperial | 50 ft | Posts | 7 posts | Yes | Yes | 10 ft | 0/0 ft |
Click Apply to load the row into the form.
Recommended Post Spacing by Fence Type
| Fence type | Typical spacing (ft) | Typical spacing (m) | Notes |
|---|---|---|---|
| Wood picket | 6–8 | 1.8–2.4 | Reduces sag; account for board width. |
| Wood privacy | 6–8 | 1.8–2.4 | Heavier panels may prefer 6 ft. |
| Vinyl panel | 6–8 | 1.8–2.4 | Follow manufacturer instructions. |
| Chain link | 7–10 | 2.1–3.0 | Wind load can reduce spacing. |
| Ranch rail | 8–12 | 2.4–3.7 | Longer spans with strong posts. |
| Ornamental steel | 6–8 | 1.8–2.4 | Panel systems often pre-sized. |
| Deer/field fence | 10–15 | 3.0–4.6 | Use braces at ends and corners. |
Values are typical ranges. Always verify with local codes and product specifications.
Quick Reference: Approximate Post Counts (including end posts)
Assumes equalized spacing. Posts ≈ round(L / d) + 1, where L is run length and d is target spacing.
| Run length | 6 ft spacing | 8 ft spacing | 10 ft spacing |
|---|---|---|---|
| 25 ft | 5 posts | 4 posts | 4 posts |
| 50 ft | 9 posts | 7 posts | 6 posts |
| 100 ft | 18 posts | 14 posts | 11 posts |
For metric: 2 m ≈ 6.56 ft, 2.4 m ≈ 7.87 ft, 3 m ≈ 9.84 ft.
Formulas Used
Definitions
- L = total run length.
- S0, S1 = start and end setbacks.
- G = sum of all gate widths.
- Leff = effective length = L − S0 − S1 − G.
Equalized spacing
- By desired spacing d: bays N = round(Leff / d) (min 1), spacing a = Leff / N.
- By panel length p: bays N = ceil(Leff / p), spacing a = Leff / N.
- By post count P (with end posts): bays N = P − 1, spacing a = Leff / N.
Fixed spacing (no equalize)
- By desired spacing d: bays N = floor(Leff / d), remainder r = Leff − N·d.
- Positions at 0, d, 2d, …, N·d. If end post is included, add final position at L.
Note: Gates are subtracted from length only; actual hinge/latch placement may require field adjustments.
How to Use
- Select units and enter the total straight run length.
- Choose a mode: by spacing, panel length, or number of posts.
- Set setbacks and optional gate widths (comma-separated).
- Decide whether to include end posts and equalize spacing.
- Click Calculate to see post count, bay spacing, and positions.
- Export the table using Download CSV or Download PDF.
FAQs
Many builds require end posts for termination strength. If your end is against a wall or existing post, you can uncheck the option.
Enter gate openings as widths. The calculator subtracts their sum from the run. Positions are shown for a continuous span; place hinge posts per your layout.
Equalized spacing makes all bays the same by slightly adjusting the target. Fixed spacing keeps your exact spacing and leaves a remainder at the end.
Treat each straight segment separately, then add posts for corners as needed. For slopes, spacing usually stays linear along the run’s projection.
Timber, soil, and hardware add variability. Mark positions, then adjust in the field to align with panels, posts, and obstructions.