| Scenario | Inputs | Recommended cut size | Roll planning example |
|---|---|---|---|
| Bed, flat cover | Rect 3×1.2 m, allowance 0.25 m, skirt 0.10 m | 3.70 × 1.90 m | Roll width 2 m → 1 panel, buy 3.70 m |
| Hoop tunnel, ends open | Rect 6×1.5 m, height 0.8 m, allowance 0.2 m, skirt 0.15 m | 6.70 × 3.80 m | Roll width 2 m, overlap 0.1 m → 2 panels, buy 13.40 m |
| Fruit tree wrap | Circ 4 m, height 2 m, overlap 0.1 m, tie 0.3 m | 2.45 × 4.60 m | Roll width 3 m → 2 panels, buy 4.90 m |
Use the calculator for your exact measurements and allowances.
This calculator estimates a practical cut size that includes a working margin for fastening and a skirt for pinning. Values are computed in meters internally and shown in your chosen units.
- Flat cover (rectangle): Net Length = L + 2×(Allowance + Skirt), Net Width = W + 2×(Allowance + Skirt)
- Drape over frame (ends open): Net Width = W + 2×Height + 2×(Allowance + Skirt)
- Drape over frame (ends closed): Net Length = L + 2×Height + 2×(Allowance + Skirt)
- Tree wrap: Net Width = Circumference + Overlap + 2×Allowance, Net Length = Height + Tie + Skirt
- Area: Area = Net Length × Net Width, then apply Waste Factor = 1 + Waste%/100
Roll planning finds the minimum panels n that satisfy: n×RollWidth − (n−1)×Overlap ≥ NetWidth. Buy length is then n×NetLength (plus waste).
- Measure your target area: bed length/width, diameter, or tree circumference and height.
- Choose Flat for top coverage, or Drape
- Set Allowance for clips/ties and Skirt for pinning or burying edges.
- If buying from a roll, enter the Roll width and your Seam overlap.
- Click Calculate. Download CSV/PDF if you want to store the estimate.
Coverage measurements that match garden geometry
Measure the footprint first, then add working margins. For beds and rows, record length and ground width to the nearest 1 cm or 1/8 in. Round beds use diameter, and trees use canopy circumference plus covered height. The calculator converts everything to a cut rectangle, so your roll purchase is straightforward.
Allowance and skirt ranges that reduce lift points
Most home beds perform well with 0.20–0.30 m (8–12 in) allowance and 0.10–0.20 m (4–8 in) skirt. Taller crops and windy sites need the upper end. If you bury edges, set skirt to your trench depth plus 0.05 m (2 in) for backfill. For clip-only installs, keep allowance at least 0.15 m (6 in).
Frame height effects in draped tunnel covers
For hoop or low-tunnel protection, net width increases by 2×frame height because the net must travel down both sides. With open ends, only width grows; with closed ends, net length also adds 2×height to wrap the end faces. A 0.80 m frame adds about 1.60 m to width. Add 0.05–0.10 m clearance if foliage touches the net.
Roll width, overlaps, and panel count planning
Roll products commonly come in 2.0 m, 3.0 m, and 4.0 m widths. When roll width is narrower than the required net width, the calculator finds the minimum number of panels where n×rollWidth − (n−1)×overlap meets the target. Typical overlaps are 0.05–0.15 m (2–6 in) depending on clips or stitching. Cut panels along roll length to minimize seams.
Waste factor and purchasing checks
Trim cuts, seam joins, and hardware openings create unavoidable losses. Use 5–10% for single-panel cuts, 10–15% for multi-panel builds, and 15–20% when you expect repairs. Compare “area with waste” to your package label, then round purchase length up to the next whole unit. Record mesh size, UV rating, and fastener spacing in notes for repeat setups. For tree bags, include 0.10 m overlap for closure, and 0.30 m tie allowance when cinching around the trunk securely above.
1) What does this calculator output?
Recommended cut length and width, netting area, and an optional roll purchase plan with panel count, seams, and buy length including waste.
2) How do I pick a mesh opening size?
Choose the smallest opening that blocks your problem birds. Smaller mesh stops smaller birds but can reduce airflow and light. Many gardens use mid-range openings and rely on good edge sealing for best results.
3) Why does drape style need more width?
Drape style adds side coverage, so width increases by twice the frame height. The net travels down both sides, plus your allowance and skirt for fastening and pinning.
4) What should I set for seam overlap?
Use 0.05–0.15 m (2–6 in). Larger overlaps hold better with clips or stitching and reduce gaps, but they increase required material and may add an extra panel.
5) What waste factor is reasonable?
Use 5–10% for single-panel covers, 10–15% when joining panels, and up to 20% for complex shapes or expected repairs. Round up your final buy length to the next package unit.
6) Can I use it for fruit trees?
Yes. Enter canopy circumference and the height you want covered, then add overlap and tie allowance for closure. The result estimates a cut rectangle that wraps and cinches cleanly.