Topsoil and turf calculator
Estimate topsoil volume and whole turf rolls from one measured lawn area while keeping depth, product coverage and delivery assumptions visible.
20 LAUNCH TOOLS
Choose a calculator
When to use it
Use after measuring the proposed lawn and choosing a project-specific topsoil depth and an actual turf product with stated roll coverage.
How it works
Base topsoil volume = area × (depth in millimetres ÷ 1,000). The allowance is applied to that volume. Turf rolls = area ÷ roll coverage, with the allowance applied once and the result rounded up to whole rolls using precision-safe exact-boundary handling.
Worked example
Assume a 30 m² lawn, a project-selected 100 mm topsoil layer, 1 m² turf rolls and a 5% allowance. Base soil volume = 30 × 0.1 = 3 m³; with allowance, 3 × 1.05 = 3.15 m³. Turf = 30 ÷ 1 = 30 rolls; 30 × 1.05 = 31.5, rounded up to 32 whole rolls.
Measurement guidance
Lawn area in square metres, topsoil depth in millimetres, turf coverage per roll in square metres and one allowance percentage. The same entered allowance is applied separately to soil volume and turf rolls.
Buying and specification checks
The area and soil depth are treated as even. The calculator does not choose a suitable soil, assess drainage, account for settlement or convert volume to weight. Roll coverage must match the selected supplier product, and one allowance may not suit both soil level variation and turf cutting waste.
Set levels, select the soil and coordinate turf delivery
The two outputs describe different products: cubic metres of soil and whole rolls of turf. Confirm each against the chosen supplier and the actual site.
- Sketch and measure the lawn, identify slopes and level changes, and confirm the finished level before choosing the entered soil depth. Use separate sections where the required fill varies instead of applying the deepest point to the whole area.
- Choose topsoil for the intended use and check the supplier's current description, testing or grade, delivery state, volume-to-weight conversion and minimum quantity. The calculator does not identify soil quality or convert cubic metres into tonnes.
- Confirm the actual dimensions or coverage of the selected turf rolls, the cutting layout and the supplier's allowance advice. Inspect the planned laying area and resolve drainage, compaction, weeds and preparation before the delivery arrives.
- Coordinate delivery with a prepared site and available labour. RHS guidance advises laying turf within 24 hours if possible; protect it from delay and follow the supplier's instructions, then water newly laid turf as conditions require so the soil beneath remains damp while it establishes.
Common mistakes
- Ignoring levels and drainage
- Assuming every roll is 1 m²
- Ignoring settlement
Practical FAQs
What topsoil depth should I enter?
Use the depth established for the actual site, intended use and finished levels. There is no universal value in the calculator; measure variable areas separately and confirm the soil specification with the supplier or appropriate adviser.
Are all turf rolls one square metre?
No. Enter the stated coverage for the exact product and check whether the supplier quotes nominal or actual dimensions. Round the result to whole rolls and confirm any minimum order.
Can I convert the topsoil result directly into tonnes?
Not without a suitable supplier conversion for the selected soil and delivery state. Moisture, composition and settlement affect weight and placed volume, so keep cubic metres and tonnes separate until verified.
When should the turf be delivered?
Arrange delivery when preparation is complete and laying can start promptly. Check the turf on arrival, follow the supplier's handling advice and plan watering for the actual weather and site conditions.
Planning guidance, not a quotation or a substitute for project-specific design and competent advice.