Turf Calculator — Rolls, Topsoil & Grass Seed

Our turf calculator divides your lawn area by the turf roll size to determine how many rolls you need, including a wastage allowance for trimming. We also calculate topsoil for preparation and provide an alternative grass seed quantity.

Turf roll calculation

Rolls needed = Area (m²) ÷ Roll size (m²) × Wastage factor

UK standard roll sizes

• Standard roll: covers 1 m² (TGA standard 406mm × 2465mm; also quoted as 0.61m × 1.64m or 0.4m × 2.5m). One roll per m².
• Big/large rolls: wider rolls for large areas, still measured and priced by area (m²).
• Retail packs: some DIY-store packs cover slightly less (around 0.83 m²) — check the coverage.

Topsoil preparation

We calculate 25mm of topsoil for ground preparation:

Topsoil volume = Area × 0.025m, Weight = Volume × 1.4 t/m³

Grass seed alternative

• New lawn (fine): 35g per m²
• New lawn (hard-wearing): 50g per m²
• Overseeding an existing lawn: 20-25g per m²

Wastage: We recommend 5% for turf — less than other materials because rolls can be butted together with minimal waste. Increase to 10% for irregular or curved areas.