Fence material formulas
Adjusted length = Plan length × √(1 + slope²) Sections per segment = Ceiling(adjusted segment length ÷ post spacing) Posts per segment = Sections + 1 Infill length = Adjusted length − gates − excluded openings Panels = Ceiling(infill length ÷ panel width × waste factor) Pickets = Ceiling(infill length ÷ effective picket coverage × waste factor) Rails = Ceiling(infill length ÷ stock rail length × rails per section × waste factor) Hole volume = π × (hole diameter ÷ 2)² × hole depth Concrete = Hole volume − gravel volume − optional post volume Concrete bags = Ceiling(concrete litres × waste factor ÷ bag yield) Project total = Materials + labour + extras + contingency + tax
The calculator converts measurements to metres before applying formulas. It then converts displayed lengths back to your chosen system. Purchase quantities always round upward to reduce shortages.
How to use the calculator
- Select the measurement system and fence type.
- Enter one total length or several individual segments.
- Set posts, boards, panels, gates, and foundations.
- Add waste percentages and current supplier prices.
- Submit the form and review rounded purchase quantities.
- Copy, print, or export the estimate for purchasing.
Measure each fence run along its actual planned route. Separate unusual sections when spacing or height changes. Confirm boundaries and buried services before construction begins.
Example fence data
| Input | Example value | Purpose |
|---|---|---|
| Total length | 100 ft | Complete measured fence route |
| Height | 6 ft | Finished fence height |
| Post spacing | 8 ft | Maximum distance between posts |
| Gate | One 4 ft gate | Opening removed from infill materials |
| Post hole | 12 in × 2.5 ft | Concrete and excavation estimate |
| Waste | 10% | Offcuts, defects, and site adjustments |
Important fence planning notes
Post spacing depends on fence weight, wind exposure, and soil. Gates require stronger posts and reliable bracing. Local standards may specify deeper foundations.
Concrete bag yields vary by brand and bag size. Use the manufacturer’s mixed-volume figure for accurate quantities. Wet ground may require extra drainage gravel.
Panel widths rarely divide every fence run evenly. The final panel may require cutting or custom framing. Keep useful offcuts for short sections.
Permit rules, boundary setbacks, and maximum heights vary. Confirm ownership before digging near property lines. Contact utility services before excavating post holes.
Frequently asked questions
How does the calculator count fence posts?
It divides each segment by its post spacing. It rounds sections upward and adds endpoint posts. Shared joined posts are counted once.
Are gate posts included?
Yes. Two gate posts are added per gate opening. Extra brace posts can also be entered separately.
How are pickets calculated?
Standard pickets use board width plus the selected gap. Board-on-board fencing uses effective overlap coverage. Shadow-box layouts count boards on both sides.
Does the calculator handle sloped ground?
Yes. Racked fences adjust the run using the slope percentage. Stepped fences can add transition posts and sections.
Why are purchase quantities rounded upward?
Retail materials are normally sold as complete pieces or packs. Upward rounding prevents partial items from understating purchases.
How much waste should I allow?
Five to ten percent suits many simple projects. Complex corners, slopes, and board patterns may require more.
Does concrete volume subtract the post?
It can. Keep the subtraction option enabled for a closer estimate. Disable it for a conservative concrete allowance.
Can existing posts be reused?
Yes. Enter the number of structurally suitable existing posts. The calculator subtracts them before applying post waste.
Can I calculate chain-link fencing?
Yes. Select chain-link fencing and enter mesh-roll, top-rail, and tie spacing. The results include rolls, rails, and ties.
Can I calculate farm wire fencing?
Yes. Enter wire strands, roll length, and staples. The calculator estimates wire length, rolls, and fasteners.
Is the project cost a contractor quotation?
No. It is a planning estimate based on your inputs. Supplier prices, taxes, labour, and site conditions can differ.