TradeCalculator.co.uk
Turf Calculator — Rolls, Topsoil & Grass Seed
Calculate turf rolls or grass seed needed for your lawn area. Includes topsoil quantities for ground preparation.
Toggle to enter area in m² instead of length × width
Length of the lawn area
Width of the lawn area
Adds 5% extra for trimming and edges
5% standard, 10% for curved/irregular areas
UK turf is sold per m² — typically £2.50–£6.50/m²
25mm standard for prep layer
Screened topsoil ~1.4 t/m³ (range 1.3–1.6)
Fine lawn minimum: 35 g/m²
Hard-wearing new lawn: 50 g/m²
Next up: related pages
How We Calculate This
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.
Frequently Asked Questions
One roll per m². Standard UK cultivated turf rolls each cover 1 m² — the TGA standard roll is 406mm x 2465mm (1 m²), and suppliers also quote it as 0.61m x 1.64m or 0.4m x 2.5m (all 1 m²). Turf is sold and priced per m². Some DIY retail packs cover slightly less (around 0.83 m²) — always confirm the coverage with your supplier. Add about 5% wastage for trimming edges and irregular shapes, so a 50 m² lawn needs roughly 53 rolls.
The best times to lay turf (also called turfing or re-turfing a lawn) in the UK are spring (March-May) and autumn (September-November) when temperatures are mild and rainfall is regular. Avoid laying turf in summer heat or during winter frost. Turf can be laid year-round if you can water it adequately, but avoid frozen or waterlogged ground.
If your existing soil is reasonable, spread 25mm of fresh topsoil and rake level before laying turf. For poor soil or new builds where topsoil has been removed, you may need 100-150mm of topsoil. This calculator includes the 25mm preparation layer — for deeper topsoil, use our Topsoil Calculator. For raised beds in the garden, see our Raised Bed Soil Calculator.
Yes — grass seed is significantly cheaper than turf, typically costing 80-90% less per m². However, seed takes 2-3 weeks to germinate and 8-12 weeks to establish a usable lawn. Turf gives instant results. Seed rate is 35-50g per m² for a new lawn. Use 35g/m² for fine lawns, 50g/m² for hard-wearing family lawns. This lawn calculator shows both turf and seed quantities.
Define lawn edges with gravel borders, paving or decking. Use our Gravel Calculator for decorative borders, Paving Slab Calculator for paved edging, or Decking Calculator for timber decking next to the lawn. A well-defined edge makes mowing easier and gives a professional finish.
Related Calculators
Was this calculator helpful?
Last updated: February 2026
Verified against UK standards · estimates only, confirm with your supplier.