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Fence Calculator
Estimate fence panels and posts for a simple straight fence run using total length, gate width, panel length, and waste allowance.
Enter your dimensions
Current unit: feet. The estimate updates automatically in your browser.
Enter the total straight-run fence length before gate deduction.
Optional. Enter the total gate width or opening width to subtract from the fence run.
Enter the length of one fence panel.
Optional extra allowance for cuts, layout changes, damage, or ordering margin.
Estimated result
Fence panels needed
Enter your inputs
Your estimate will appear here automatically once the required inputs are valid.
Guide
How to use this estimate
How the fence calculator works
This calculator subtracts the optional gate width from the total straight fence length, floors the result at zero, adds optional waste allowance, and divides by the length of one fence panel.
The panel count is rounded up because fence panels are normally bought as full pieces. The post estimate uses panels plus one, which assumes a simple straight run rather than an enclosed layout with corners or custom gate posts.
What to measure
Measure the total straight fence run before gate deduction. Then enter the total gate width or opening width if part of that run will not use fence panels.
Enter the length of one fence panel from the product listing or supplier. Do not use this V1 calculator for enclosed yards, corner-heavy layouts, chain-link systems, or fences where post spacing is independent of panel length.
Example fence calculation
- Total fence length: 100 feet
- Gate width: 4 feet
- Panel length: 8 feet
- Waste allowance: 10%
- Net length: 100 - 4 = 96 feet
- Adjusted length: 96 × 1.10 = 105.6 feet
- Panels needed: 105.6 ÷ 8 = 13.2, rounded up to 14 panels
- Posts needed for a straight run: 14 + 1 = 15 posts
Estimated fence materials: 14 panels and 15 posts for a simple straight fence run.
Quick reference
| Item | Value | Note |
|---|---|---|
| Panel formula | ceil(adjusted length ÷ panel length) | Adjusted length subtracts gate width and adds optional waste allowance. |
| Post formula | panels + 1 | This assumes a simple straight run, not an enclosed yard or corner layout. |
| Gate deduction | Subtracted from total length | Use this for gates or openings where fence panels will not be installed. |
Common mistakes to avoid
- Using this straight-run calculator for a full enclosed yard with corners.
- Forgetting to subtract gate width or openings from the fence run.
- Assuming post needs are the same for every fence system and layout.
Frequently asked questions
Why does the fence calculator round up panels?
Fence panels are normally bought as full pieces. If the calculation gives 13.2 panels, you still need 14 full panels for that straight run.
Why are posts calculated as panels plus one?
For a simple straight run, each panel sits between posts, so a run with 14 panels needs 15 posts. This does not cover corners, enclosed layouts, gate posts, terminal posts, or custom fence systems.
What happens if gate width is larger than total fence length?
The calculator floors the net fence length at zero. In that case it returns zero panels and zero posts instead of showing a negative or confusing material estimate.