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Work out how many rolls of turf you need for a new lawn. Choose the shape, enter its size, pick the edges and the topsoil depth, and press Calculate to see the rolls to order with extra for cutting, the topsoil in m³ and bulk bags, and the lawn edging.
| Depth | Topsoil | 0.5 m³ Bulk Bags |
|---|
Topsoil for the same lawn at each depth. Bulk bag sizes vary, so check the volume with your supplier.
You get the number of turf rolls to order, the lawn area, the topsoil in cubic metres and 0.5 m³ bulk bags, and the length of lawn edging. A table shows the topsoil at other depths, and you can copy the result or save it as a PDF.
Measure in metres and work out the area of each part of the lawn:
| Shape | Area | Example |
|---|---|---|
| Rectangle | Length × width | 8 × 6 m = 48 m² |
| Circle | π × diameter² ÷ 4 | 4 m across = 12.57 m² |
| Right-angled triangle | Base × height ÷ 2 | 6 × 4 m = 12 m² |
For an odd-shaped lawn, Rolawn suggests splitting it into rectangles on a sketch, measuring each one and adding them up; curved edges can be measured as the nearest rectangle, since the extra for cutting covers the trimming. Then enter the total with the "I know the area" option. Do not take off small obstacles such as a washing line post.
UK turf is sold by the square metre, in rolls of about 1 m². Rolawn rolls measure roughly 610 mm wide by 1640 mm long when cut. So the number of rolls is the area in m², plus a little extra:
Rolls = lawn area × (1 + extra), rounded up
Order everything in one go: turf from a later harvest may not match in colour or thickness, and turf does not keep, so you cannot hold spare rolls for long.
Rolawn recommends 100 to 150 mm of topsoil for a lawn, which gives the roots room to grow and holds water through dry spells. If your existing soil is good but a little thin or uneven, 50 mm of new topsoil may be enough to level it.
Topsoil (m³) = lawn area (m²) × depth (m)
| Depth | Topsoil | 0.5 m³ bulk bags |
|---|---|---|
| 50 mm | 2.5 m³ | 5 |
| 100 mm | 5.0 m³ | 10 |
| 150 mm | 7.5 m³ | 15 |
Bulk bag sizes vary between suppliers. Rolawn's Turf & Lawn Seeding Topsoil comes in bags of about 0.5 m³, which is what the calculator uses; other bags hold 0.7 m³ or more, so check before you order. For large areas, a loose load delivered by tipper can be cheaper. Our gravel calculator works out other bulk materials the same way.
Turf will not hide bumps and hollows, so take time over the levelling. If the lawn will be next to a patio or path, our concrete calculator and decking calculator help plan those too.
Turf gives you a finished lawn the day it goes down and can usually be walked on lightly within a few weeks, which suits families, pets and sloping ground where seed might wash away. It costs more than seed and is heavy to handle, and it needs laying straight away and watering well while it roots. Grass seed is far cheaper, light to carry and easy to spread, but takes longer to establish, needs the right weather, and is at the mercy of birds and weeds while it grows. Both need the same ground preparation, so the topsoil figures from this calculator apply either way. Many people turf the main lawn and sow seed to patch worn areas later.
An 8 × 6 m rectangular back lawn with straight edges and 100 mm of new topsoil:
A 4 m circular lawn is 12.57 m²; with 10% extra for the curve, order 14 rolls.
Rectangle: L × W · Circle: π × D² ÷ 4 · Triangle: base × height ÷ 2 · Rolls = area × 1.05 or 1.10, rounded up
Topsoil is the lawn area times the depth, and bulk bags are 0.5 m³ each. Lawn edging is the perimeter: twice the length plus the width, π × diameter for a circle, or the three sides of a right-angled triangle. The plan drawing shows rolls of about 0.61 × 1.64 m in a staggered pattern. Allow a little more topsoil if the ground needs filling as well as covering, as soil settles after it is firmed.
Work out the lawn area in m² and add 5% for straight edges or 10% for curves; with rolls of about 1 m², that is the number of rolls. An 8 × 6 m lawn needs about 51 rolls.
Most UK turf rolls cover about 1 m². Rolawn rolls are roughly 610 mm wide and 1640 mm long.
At least 5% for straight edges, as Rolawn recommends, and about 10% for curved or awkward shapes.
100 to 150 mm for a new lawn. 50 mm can be enough to top up and level reasonable existing soil.
5 m³ at 100 mm deep, or 7.5 m³ at 150 mm, which is 10 or 15 bulk bags of 0.5 m³.
Yes, if the soil is good, weed-free and levelled. Dig it over, rake it level, firm it and rake in a pre-turf fertiliser first.
As soon as possible, ideally the same day, because turf dries out and yellows while it is rolled up.
Soak it straight after laying, then keep it moist every day in dry weather until the roots take hold, usually two to three weeks.
Roll size, extra to order, measuring method and topsoil depths from Rolawn. Topsoil bag volume from Rolawn Turf & Lawn Seeding Topsoil product data. Reviewed November 2026.