Confirm the line before measuring
Do not assume an existing fence, hedge, or worn path is the legal property line. Confirm ownership, survey information, easements, setbacks, permits, shared-fence rules, and access requirements as appropriate for the location. Mark the proposed alignment only after those questions are resolved.
Before digging, contact the utility notification service that applies to the project location and follow its instructions and waiting period. Private lines may require separate locating. The DigAlert source linked here is a California example, not a global rule.
Measure each run separately
A run is a straight or deliberately modeled segment between topology changes. Record its length, start point, end point, corners, connections, and gate openings. Naming runs clockwise around the property makes the sketch easier to audit.
Sloped ground requires a decision about whether panels step or follow grade. Measure the layout method the selected fence system requires. Horizontal map distance, slope distance, and panel length may not be interchangeable.
Treat post spacing as a maximum
If a 100 ft run has a maximum spacing of 8 ft, dividing gives 12.5. Round up to 13 sections so the calculated spacing does not exceed 8 ft. A straight run with 13 sections has 14 endpoint and intermediate line posts before gates, corners, or shared connections are adjusted.
The default 8 ft or displayed 2.4 m is an editable planning value, not a structural recommendation. Fence height, material, panel system, wind, soil, frost, grade, loads, local rules, and manufacturer instructions can require another layout.
Endpoints, corners, and connected runs
Each independent straight run normally needs both endpoints. Two connected runs can share a corner post when the design permits. If the second run is entered as sharing its starting post, the calculator avoids counting that endpoint twice.
Corners and line transitions can require larger or differently reinforced posts. Count types separately on the field sketch even when the initial shopping list combines them.
Gates and openings
Subtract gate width from the fence run before calculating ordinary sections. Then add the posts and hardware required by the gate design. Gate leaf width, hinge and latch clearances, double gates, automation, grade, and structural loads affect the real opening and post details.
Do not place a gate by subtracting its nominal width only. Confirm the manufacturer’s rough opening and hardware instructions.
Pickets, rails, panels, and concrete
Rails equal sections times rails per section. Picket count depends on usable run, picket width, and gap. The result can add an explicit extra percentage for cuts and defects.
Post-hole concrete uses hole diameter and depth, subtracts embedded post volume, multiplies by posts, applies an allowance, and divides by bag yield. The calculator does not choose a safe footing. Frost, wind, soil, drainage, post material, fence height, gate load, and code can control hole dimensions.
Measurement worksheet
| Run | Length | Shares start post | Gates | Grade or corner notes |
|---|---|---|---|---|
| Run 1 | No | Include unit | ||
| Run 2 | Yes or no | Connected endpoint | ||
| Run 3 | Yes or no | Slope method |
Also record maximum spacing or panel width, rails per section, picket width and gap, post types, gate opening details, hole diameter and depth, post displacement, bag yield, prices, and the utility locate reference.
Common mistakes
- Dividing and rounding sections down, which exceeds the selected maximum spacing.
- Counting every connected run as independent and duplicating corner posts.
- Leaving gate width in usable fence length and adding gate posts afterward.
- Treating nominal picket or panel dimensions as installed coverage without checking gaps.
- Using one hole size for every post without reviewing loads and local conditions.
- Digging before utility location, property, permit, and easement checks are complete.
- Treating a material quantity as a structural or code-compliant design.
Limits and checks
The calculator models straight runs and declared connections. Curves, stepped panels, racked panels, custom corners, retaining conditions, masonry, privacy screens, severe slopes, and mixed systems need a more detailed layout. Price totals omit labor, tools, permits, delivery, demolition, disposal, finishes, and unentered hardware.
Before ordering, compare the plan with current manufacturer instructions, local requirements, property information, utility responses, actual grade, soil and drainage, gate details, and any engineering needs. Resolve discrepancies before excavation.