About the landscape fabric calculator
Landscape fabric is sold in rolls of a fixed width, and seams need to overlap so weeds can’t push through. That means you’ll always buy more fabric than the bed’s area. This calculator works out strips and rolls, and tries both directions to find the layout that uses less fabric.
How to use this calculator
- Enter the area’s length and width.
- Enter the roll width and length from the package.
- Enter the seam overlap the manufacturer recommends.
- Add a price per roll for cost.
Worked examples
- 20 × 6 ft area, 3 × 50 ft rolls, 6 in overlap
- Effective width 2.5 ft; running across the width: 8 strips × 6 ft = 48 ft
- 48 × 1.05 = 50.4 ft
2 rolls.
Measurement guidance
Where fabric helps
Fabric is commonly used under gravel and stone. Under organic mulch it can block the mulch from improving the soil over time.
Pin it down
Secure seams and edges with landscape staples according to the package instructions.
Frequently asked questions
How much should landscape fabric overlap?
Follow the manufacturer’s recommendation printed on the package.
Should I put fabric under mulch?
Opinions differ. It can reduce weeds initially, but organic mulch breaking down on top of fabric eventually becomes a place where weeds grow.
Which direction should I run the strips?
Whichever uses less fabric. The calculator compares both and tells you.