Your measurements
Results
Fill in every measurement above and your results will appear here.
Your shopping list
| Material | Quantity | Notes |
|---|
How the turf calculator works
Multiply the length by the width and you have the area in square metres. The calculator then adds your cutting allowance — 5% by default, because every lawn has edges to trim and corners to work around — and divides by the roll size, rounding up to the next whole roll.
Roll size is the number people get wrong. Most UK turf is cut into 1 m² rolls, but some suppliers sell 1.2 m² rolls, and a few sell large 2 m² rolls that need two people to lift. A 12.5 m × 8.2 m lawn is 102.5 m²; with 5% for cutting that is 107.6 m², so 108 rolls at 1 m² each — or 90 rolls if your supplier's rolls are 1.2 m². Same lawn, very different order.
If you need to raise the level, enter a topsoil depth. The calculator works out the volume at your chosen depth and converts it using a typical screened topsoil bulk density of 1.5 tonnes per cubic metre, then shows it in tonnes and in 850 kg bulk bags. As a rough guide, a 20 mm dressing over 100 m² is about three tonnes. Turf starter fertiliser, if you tick it, is calculated at 35 g per m² — the usual rate for spreading under new turf.
Preparing the ground properly
Turf on a badly prepared surface will fail, however good the turf is. Strip the old turf or vegetation, dig or rotavate the top 100–150 mm, remove stones and roots, then firm the surface by treading it in a grid pattern. Rake it level and leave it to settle for a few days before laying; a final light rake and a firm surface is what you are after. Do not add loose topsoil and lay turf straight onto it without firming — the turf will sink unevenly and the joins will open up.
Ordering and laying day
Turf is a living product and degrades quickly once cut. Order it for the day you can lay it, and lay it within 24 hours of delivery — sooner in warm weather. Stack rolls in the shade, unroll them within a few hours, stagger the joins like brickwork, and butt them tightly together without stretching. Keep off the new lawn for two to three weeks and water it daily for the first fortnight, more often in hot weather. Avoid laying in frost or in the middle of a drought.
Turf FAQs
How many rolls of turf do I need for 100 m²?
105 rolls at 1 m² each, allowing 5% for cutting in. If you want no spare at all, 100 rolls will technically cover it, but you will be short the moment you meet a curved edge or a cut corner.
What size are turf rolls in the UK?
1 m² is the standard, sold as a roll roughly 1.5–1.7 m long and about 0.6 m wide. Some growers supply 1.2 m² rolls, which are heavier and usually better value per square metre. Always check the stated area — a "roll" is not a standard unit.
How much topsoil do I need under turf?
The turf itself needs only a fine, firm surface — a 10–20 mm dressing is plenty for levelling. Where you are building the level up properly, work on 100–150 mm of good topsoil over the subsoil. The calculator converts whatever depth you enter into tonnes and bulk bags.
When is the best time to lay turf?
Spring and early autumn are ideal: the soil is warm and moist, so roots establish quickly. Turf can be laid in summer if you water it consistently, and in mild winters as long as the ground is not frozen and there is no hard frost forecast.
How long before I can use a new lawn?
Keep off it entirely for two to three weeks, then start with light foot traffic. First cut when it reaches about 50 mm and take off no more than a third of the height. It takes a full growing season for the roots to knit into the soil properly.