Garden: turf, topsoil, bark, gravel and raised beds
Bulk garden materials are sold by the cubic metre or tonne, bags by the litre, which is why it is easy to buy the wrong amount. 10 m² of border mulched 50 mm deep takes 0.55 m³ of bark, or 11 bags of 50 litres with 10% extra. For a new lawn, 30 m² is 32 rolls of 1 m² turf with 5% extra.
This page brings together our UK calculators and guides for lawns, borders and beds: turf and seed, topsoil, bark, gravel, raised beds, artificial grass and water butts.
Bark and topsoil by area
Worked out by the bark and topsoil calculators with 10% extra: bark at 50 mm deep, topsoil at 100 mm, both in 50 litre bags.
| Area (m²) | Bark at 50 mm (m³) | Bark (50 L bags) | Topsoil at 100 mm (m³) | Topsoil (50 L bags) |
|---|---|---|---|---|
| 5 | 0.28 | 6 | 0.55 | 11 |
| 10 | 0.55 | 11 | 1.10 | 22 |
| 20 | 1.10 | 22 | 2.20 | 44 |
| 30 | 1.65 | 33 | 3.30 | 66 |
| 50 | 2.75 | 55 | 5.50 | 110 |
| 100 | 5.50 | 110 | 11.00 | 220 |
Topsoil, bark and gravel
Over about a cubic metre, a bulk bag is usually cheaper than small bags. Gravel is sold by the tonne: 20 m² at 50 mm deep is 1.68 tonnes, or 3 bulk bags.
A new lawn: turf or seed
Turf gives an instant lawn and must be laid within a day or so of delivery; seed is cheaper and best sown in early autumn or spring. Either way, prepare the soil first. The new lawn calculator lists both routes.
Raised beds and water butts
The raised bed calculator counts sleepers or boards, posts, screws and bags of soil to fill them. A water butt fed from a shed or house roof saves mains water for the beds.
Every calculator for this topic
Guides
- Common Mistakes Laying a Turf Lawn (UK): Rolls, Topsoil, WateringTurf mistakes: ordering too few rolls, a thin topsoil bed. A 6 × 5 m lawn takes 32 rolls of 1 m² with 5% extra and 1.7 m³ of topsoil at 50 mm.
- How Big a Water Butt Do I Need? Roof Area, Rainfall and Litres (UK)A 20 m² garage roof collects about 13,600 litres of rain a year and 160 litres in a 10 mm shower. Charts of rain collected by roof, region and butt size.
- How Much Artificial Grass Do I Need? Roll, Sub-base and Sand (UK)A 5 × 4 m lawn needs 5.25 m of 4 m wide artificial grass, 2.3 tonnes of MOT Type 1 and 0.8 tonnes of sharp sand. Charts by lawn size and the base.
- How Much Gravel Do I Need? Tonnes, Bulk Bags and Coverage (UK)A 5 × 4 m area at 50 mm deep needs 1.7 tonnes of 20 mm gravel, 3 bulk bags. One tonne covers 12.5 m² at 50 mm. Charts by area, depth and material.
- Turf or Grass Seed for a New Lawn? What Each Needs (UK)Compare laying turf with sowing grass seed for a 6 x 5 m lawn: the quantities to buy, timing, effort and when each is the right choice in the UK.
- How Much Grass Seed Do I Need Per m²? UK Lawn GuideHow many kilograms of grass seed a new lawn or an overseeded patch needs, with a chart by lawn size, how seed compares with turf, and when to sow.
- How Much Turf Do I Need? Rolls, Pallets and Topsoil (UK)Turf quantities by lawn size, how many rolls make a pallet, the topsoil to prepare the ground, and the best time to lay a new lawn in the UK.
- Topsoil and Bark: How Much Do I Need for My Garden? (UK)How many cubic metres and bags of topsoil and bark mulch you need for a lawn, border or bed, with charts by area and depth, and how far a cubic metre goes.
Other guides that use these calculators: How Many Sleepers for a Retaining Wall? Posts and Screws (UK) · Drain Fall and Gradient: How Much Fall Does a Drain Need? (UK) · Gravel or Block Paving Driveway? What Each Needs, 6 x 5 m · How Many Paving Slabs Do I Need? Slabs per m² Chart (UK) · How Much Concrete Do I Need? m³ and Bag Charts (UK) · How Much Guttering Do I Need? Lengths, Brackets and Fall (UK) · Block Paving Driveway: Blocks, Sub-base and Sand Needed · Gravel Driveway: Tonnes of Stone and Materials Needed (UK) · Patio Materials List UK: Slabs, MOT Type 1 and Sand · Concrete Shed Base UK: How Much Concrete, Which Mix, What to Buy
Answers for common sizes
Already know the size? These pages give the worked answer for one common size each, with the inputs filled in so you can adjust them.
Project planners
Planning the whole job rather than one material? These step-by-step planners put the calculators above in the order you will need them.
Frequently asked questions
How much bark do I need for 10 m²?
0.55 m³ at 50 mm deep, or 11 bags of 50 litres, with 10% extra.
How much turf for 30 m²?
32 rolls of 1 m², with 5% extra for cutting to shape.
How deep should bark mulch be?
About 50 to 75 mm to suppress weeds. Keep it clear of stems and tree trunks.
When should I lay turf or sow lawn seed?
Autumn and spring are best for both. Turf can go down most of the year if you can water it, but not on frozen or waterlogged ground.
Related topics
Estimates only. Quantities depend on your materials, site and supplier, so check pack sizes and coverage on the label. Check the Building Regulations and any planning rules for anything structural or close to a boundary. How we calculate.