Why Accurate Fence Length Matters
Fence length drives material cost, labor time, and layout accuracy in garden projects. A 5% measuring error on a 120-ft perimeter can add 6 ft of extra panels, posts, and fasteners. This calculator converts common garden shapes and mixed runs into a single net length so you can estimate purchases with fewer surprises.
Inputs That Influence Total Run
Perimeter is calculated from your selected shape. Rectangles use 2×(L+W). Circles use π×D or 2×π×R. Polygons and custom segments sum each side or run. Unit conversion keeps the math consistent: 1 yd = 3 ft, 1 m = 3.28084 ft. Enter measurements as built dimensions, not planter interior size, to avoid underestimating.
Gate Allowances and Waste Factors
Gates reduce fencing needed because that opening is not fenced. Net fence length = Perimeter − Gate Width. A waste factor then adds contingency for cuts, overlaps, bracing, and minor grade changes: Materials Length = Net Length × (1 + Waste%/100). For neat panel systems, 3–7% is typical; for uneven terrain or many corners, 7–12% helps.
Post Count and Spacing Planning
Posts are estimated from spacing and corners. A practical rule is Posts ≈ ceil(Net Length / Spacing) + Corner Posts + Gate Posts. This tool assumes corners and gate hinges need dedicated posts, then distributes line posts by spacing. Tighter spacing improves rigidity but increases hardware count; 6 ft spacing suits lighter mesh, while 8 ft often fits panel fencing.
Using Results for Ordering and Layout
Use the net length for design validation, then use the materials length for ordering. Compare the suggested post count with your layout sketch, especially when runs are short. If you plan end braces, add extra posts and concrete. Save CSV for quotes and PDF for job folders. For sloped beds, measure along the ground line rather than the map distance. When mixing materials, run the calculator twice—once for each area—to separate quantities. Round up to panel lengths to match supplier packaging.