How the calculator works it out
Most artificial grass calculators multiply length by width and add 10 %. That can be well out, because turf is sold by the roll width. Suppliers cut rolls to any length, but the width is fixed, and every piece must be laid with the fibres pointing the same way or the lawn looks patchy in different light. So a lawn is always covered by parallel strips, each the full roll width and the full length of the lawn plus a trimming allowance.
turf to buy = total strip width × strip length · joins = strips − 1, each as long as the strip
The calculator tries every mix of the roll widths on offer, keeps the one that buys the fewest square metres, and on a tie the one with fewer joins. It does this with the strips running both ways and picks the better direction, unless you fix it. Direction matters: a 5 m wide lawn in 4 m rolls needs two strips and wastes 3 m of width, while a 4 m wide one needs a single piece.
Roll sizes in Australia
| Width | Where you'll see it | Length |
|---|---|---|
| 2 m | Narrow strips, balconies, the second strip beside a 4 m roll | Cut to length |
| 3.7 m | Much Australian-made turf, such as All Seasons Synthetic Turf's 3.71 m rolls | 20 m rolls; part rolls in 0.5 m steps |
| 4 m | Widely sold, for example by Ausgrass (alongside 2 m) and Ezy Decking | 20–25 m rolls, or cut to length |
| 5 m | Large lawns, where fewer joins matter | Cut to length |
Check the widths for the exact product before you order: they vary by range, even from one supplier. Premier Grass makes custom lengths up to 30 m.
What goes underneath
The base decides how flat the lawn looks and how well it drains. The Australian Paving Centre's guide sets out a typical build:
- Dig out 75–100 mm and remove roots and organic matter.
- Lay 50–70 mm of fine crushed rock and compact it, with a fall of at least 1 in 50 so water drains away.
- Screed 10–20 mm of crusher dust on top and compact it, finishing about 15 mm below the final height.
Next Generation Turf specifies 75 mm of road base for foot traffic and 100 mm where light vehicles will drive, with a 20 mm screed. Artificial Grass Online asks for at least 50 mm of compacted crusher dust. The gravel calculator converts the layers into tonnes for other materials, and the trailer calculator works out the trips.
Sand infill
After laying, kiln-dried silica sand is spread and brushed into the pile. Suppliers' rates depend on pile height:
| Pile height | Sand per m² | 25 kg bags for 40 m² |
|---|---|---|
| 30 mm | 6 kg | 10 |
| 35 mm | 8 kg | 13 |
| 40 mm | 10 kg | 16 |
| 45 mm | 12 kg | 20 |
The rates are Next Generation Turf's. The Australian Paving Centre suggests 5–8 kg/m², enough for at least 10 mm of sand between the blades, and Artificial Grass Online about 10 kg/m², filling roughly half the pile height.
Joins and fixing
- Joins: lay the pieces with the pile the same way, fold the edges back and stick them onto joining tape centred under the join. The Australian Paving Centre uses 120 mm self-adhesive tape; Next Generation Turf uses a 300 mm geo-fabric strip with adhesive where traffic is heavy. Trim the excess only after every join is done.
- Pins: Next Generation Turf fixes the edges with 150 mm galvanised pins every 300 mm and adds one pin per m² inside.
- U-pegs: the Australian Paving Centre uses 180 mm U-pegs within 75 mm of the outside edge, 800–1,000 mm apart, with the pegs along a join no closer than 300 mm to it.
What it costs
Premier Grass's 2026 price guide puts supply-only turf at $25–40 per m² for budget ranges, $40–60 mid-range and $60 or more for premium. Installed, it quotes $75–160 per m², with the turf about 40 % of the job and base preparation and labour about 30 % each. The offcuts this calculator shows are part of the turf cost, so the layout matters: on a lawn that almost fits one width, a different roll width can save more than a cheaper product.
Artificial grass questions
How much artificial grass do I need?
Enough full-width strips to cover the width plus about 100 mm, each as long as the lawn plus about 100 mm. An 8 × 5 m lawn with 4 m and 2 m rolls needs a 4 m and a 2 m strip, each 8.1 m long: 48.6 m² for a 40 m² lawn.
What width does artificial grass come in?
Usually 2 m, 3.7 m or 4 m in Australia, and sometimes 5 m. Suppliers cut rolls to length but sell the full width.
How much sand goes in artificial grass?
About 6 kg/m² for 30 mm pile, rising to 12 kg/m² for 45 mm pile, in kiln-dried silica sand. A 40 m² lawn with 35 mm pile takes about 320 kg, or 13 bags of 25 kg.
How deep should the base be under artificial grass?
Dig out 75–100 mm. Lay 50–70 mm of compacted fine crushed rock, or 75 mm of road base for foot traffic and 100 mm for light vehicles, then 10–20 mm of crusher dust, with a fall of at least 1 in 50.
Sources and method
- Australian Paving Centre, Installation guide: artificial grass – excavation, crushed rock, crusher dust, fall, U-pegs, joining tape, sand infill.
- Next Generation Turf, How to install artificial grass – trimming allowance, road base depths, pins, infill by pile height.
- Artificial Grass Online, How to measure and install artificial grass – 3.7 m rolls, crusher dust base, 10 kg/m² infill.
- All Seasons Synthetic Turf, What size does artificial grass come in? – 3.71 × 20 m rolls, part rolls in 0.5 m steps; Classic Backyards, How do you measure for artificial grass? – 2, 4 and 5 m widths, pile direction.
- Premier Grass, How much does artificial grass cost in Australia? (2026) – supply and installed prices, cost split.
- Densities: compacted road base 2.2 t/m³ (as on the paver calculator); crusher dust 1.6 t/m³ loose (as on the gravel calculator).
Written by DueRiva · Last reviewed 23 September 2026 · Report an error