Artificial grass is sold off a roll of fixed width, cut to length. The area of the lawn is only a starting point: what you pay for is whole strips of the roll.
Strips, not square metres
Namgrass and B&Q list rolls 2 m and 4 m wide. Australian specialists list the same widths, and Bunnings sells Tuff Turf 1.8 m wide by the metre.
A 6 m by 4.5 m lawn is 27 m². With 50 mm at each edge for trimming it is 6.1 by 4.6 m. On a 4 m roll, two strips running across the width, each 4.6 m long, cover it: 9.2 m of roll, 36.8 m², one seam.
Common lawn sizes
The calculator tries the strips both ways and keeps the one that buys less grass. A narrower roll sometimes wastes less, at the cost of more seams.
| Lawn | 4 m roll | Bought | Seams | 2 m roll | Bought | Seams |
|---|---|---|---|---|---|---|
| 4 × 3 m | 4.1 m | 16.4 m² | 0 | 8.2 m | 16.4 m² | 1 |
| 5 × 3.5 m | 5.1 m | 20.4 m² | 0 | 10.2 m | 20.4 m² | 1 |
| 6 × 4.5 m | 9.2 m | 36.8 m² | 1 | 18.3 m | 36.6 m² | 2 |
| 8 × 5 m | 15.3 m | 61.2 m² | 2 | 24.3 m | 48.6 m² | 2 |
| 10 × 6 m | 18.3 m | 73.2 m² | 2 | 36.6 m | 73.2 m² | 5 |
Pile direction and seams
All strips should run the same way so the pile leans in one direction; otherwise each strip looks a different shade. That is why the calculator never turns one strip sideways to save an offcut.
Seams are joined with tape and adhesive underneath. The joining tape is the number of seams times the strip length.
Under the grass
The sub-base, sharp sand or grano dust and weed membrane are not counted here. The Tonnes calculator turns a depth over the lawn into tonnes and bulk bags.
Figures are estimates for a shopping list. Check the pack or datasheet before you buy.