Landscape Fabric Calculator
Enter your project dimensions to estimate square footage, rolls needed, leftover fabric, and approximate staple count.
Quick Answer
Measure length × width, add 15% for seam overlap and waste, then divide by roll coverage. A 200 sq ft bed needs ~230 sq ft of fabric — one 4 × 100 ft roll (400 sq ft) covers it comfortably.
Project Area
Overlap & Waste Allowance
Roll Size
Price Per Roll (optional)
Enter your project length and width above to see results.
Common Roll Sizes
Landscape fabric is sold by the roll. Roll width matters as much as total coverage — a narrow bed may be more efficiently covered with a 3-foot roll than with a 6-foot roll that requires cutting and creates extra seams.
| Roll Size | Total Coverage |
|---|---|
| 3 ft × 50 ft | 150 sq ft |
| 3 ft × 100 ft | 300 sq ft |
| 4 ft × 50 ft | 200 sq ft |
| 4 ft × 100 ft | 400 sq ft |
| 6 ft × 100 ft | 600 sq ft |
| 6 ft × 300 ft | 1,800 sq ft |
If your bed is wider than the roll, you will need multiple side-by-side strips with overlapping seams. The calculator warns you when this applies and recommends the number of strips.
Where Landscape Fabric Works — and Where It Doesn't
✓ Use it under
- Permanent decorative rock beds
- River rock and dry creek beds
- Gravel paths and walkways
- Foundation shrub plantings
- Drainage swales (permeable geotextile)
✗ Skip it under
- Organic mulch in planted beds
- Vegetable gardens
- Annual flower beds
- Areas replanted each season
- Beds where soil improvement matters
The most common mistake is installing fabric under organic mulch. As mulch decomposes it builds up above the fabric, eventually creating a seedbed where weeds grow just fine. Fabric is most effective under permanent, non-organic materials that won't decompose into a growing medium.
For a full comparison of permanent rock beds vs. organic mulch, see River Rock vs. Mulch. For guidance on whether fabric is right for your specific rock installation, see Should You Put Landscape Fabric Under River Rock?
What to Buy
For most permanent rock bed installations, the key items are the fabric itself, staples to hold it in place, and an edging product to contain the rock cleanly.
What to Calculate Next
Once you have your fabric estimate, use the appropriate material calculator for the covering layer.
River Rock Calculator
Cubic yards, tons, and cost for decorative stone beds
Gravel Calculator
Volume and cost for gravel paths and driveways
Mulch Calculator
Cubic yards and bags for organic mulch beds
Driveway Gravel Calculator
Gravel depth and tonnage for driveways
French Drain Calculator
Stone, pipe, and fabric for drainage trenches
Cubic Yards Calculator
Universal converter for any material
Frequently Asked Questions
How do I calculate how much landscape fabric I need?
Multiply the length of the area by the width to get square footage. Then add 10–15% for seam overlap and waste. Divide the adjusted total by the coverage per roll to get the number of rolls. For example: a 20 × 10 ft bed is 200 sq ft. At 15% waste, you need 230 sq ft — one 4 × 100 ft roll (400 sq ft) is more than enough.
How much should landscape fabric overlap at seams?
Overlap adjoining sheets by at least 6 inches. Use 8–12 inches in areas with heavy weed pressure, sloped ground, loose soil, or where water regularly flows through. Secure both layers with landscape staples — don't rely on the weight of the covering material alone.
How many landscape staples do I need?
Plan for roughly 1 staple per 2 linear feet along edges and seams, plus additional staples around curves, plant openings, and slopes. The calculator estimates this automatically based on the perimeter and area of your project.
What is the best landscape fabric for under river rock?
Heavy-duty woven landscape fabric is the standard choice under decorative rock. It suppresses weeds, allows water to drain through, and resists tearing when rock is installed or shifted. Avoid thin plastic sheeting — it blocks drainage and degrades faster.
Should I put landscape fabric under mulch?
Generally not in planted beds. Organic mulch breaks down over time, eventually creating a layer of organic matter above the fabric where weeds can grow. Fabric is most useful under permanent, non-organic coverings like river rock, pea gravel, or decorative stone.