Weed Barrier / Landscape Fabric Calculator
Calculate rolls of landscape fabric needed from garden bed dimensions in feet or meters.
Returns square footage, roll count with 10% overlap, and staple count.
Landscape weed barrier (ground cloth / weed fabric) blocks sunlight to prevent weed germination while allowing water and air to pass through. Accurate coverage calculation prevents costly mid-project shortages.
Coverage formula:
Area to Cover (sq ft) = Total Bed Area − Area of Existing Plants
Rolls Needed = Area to Cover / (Roll Width × Roll Length)
Overlap allowance: Add 10–20% extra for edge overlaps (typically 6–12 inches between strips), rocks, and cutting waste:
Adjusted Area = Area to Cover × 1.15
Worked example: A garden bed 15 ft × 25 ft = 375 sq ft total
- Existing shrub areas: 3 × 4 ft circles = 37.7 sq ft
- Net coverage needed: 375 − 37.7 = 337.3 sq ft
- With 15% overlap waste: 337.3 × 1.15 = 388 sq ft needed
- Standard roll: 3 ft × 100 ft = 300 sq ft → buy 2 rolls (600 sq ft; leftover useful for future beds)
Weed barrier types and lifespans:
| Type | Lifespan | Water Flow | Best Use |
|---|---|---|---|
| Woven polypropylene | 5–20 years | Good | Permanent beds, pathways |
| Non-woven spunbond | 3–5 years | Excellent | Vegetable gardens |
| Plastic sheeting | 1–3 years | None (except holes) | Solarization, raised beds |
| Biodegradable jute | 1–2 years | Excellent | Eco-friendly short-term use |
Mulch layer required on top: Weed barrier alone still allows weed seeds to germinate in surface dirt. Always top with 2–4 inches of mulch to suppress light and soil erosion.
Staple spacing: Use landscape fabric staples every 12 inches along edges and every 18 inches through the middle. In windy areas, reduce to 8–10 inches at all edges.