How much soil do I need? Multiply the area in square metres by the depth in metres to get cubic metres, then add a small allowance for settling. The same sum works for mulch, and the biggest mistake is guessing the depth.
This guide gives you the formula, depth guides for beds and lawns, a litres-to-cubic-metre conversion and the Sydney labour costs if you hire help. Material prices change by supplier, so ask for a quote from your local yard.
Key points
- Cubic metres equal area (m²) multiplied by depth (m); one cubic metre is 1000 litres (indicative — check the supplier’s measure).
- Bulk loads usually cost less per litre than bags, but bags suit small beds and tight access.
- Material prices vary widely (indicative — ask your supplier), but a Sydney gardener costs about $52 to $115 per hour, with $75 typical (October 2026).
- Keep mulch clear of walls and trunks, and book a licensed pest controller if you see termites.
How much soil do I need: the formula
| Step | What to do | Example |
|---|---|---|
| 1. Measure | Length by width of the bed or lawn in metres | A bed 5 m by 2 m is 10 m² (indicative example) |
| 2. Choose a depth | Convert millimetres to metres | 50 mm is 0.05 m (indicative example) |
| 3. Multiply | Area by depth gives cubic metres | 10 m² by 0.05 m is 0.5 m³ (indicative example) |
| 4. Add a buffer | Allow extra for settling and uneven ground | A modest top-up (indicative — ask your supplier) |
| 5. Convert to litres | Multiply cubic metres by 1000 for litres (indicative — check the supplier’s measure) | 0.5 m³ is 500 litres (indicative example) |
How many litres in a cubic metre of soil?
A cubic metre is 1000 litres (indicative — check the supplier’s measure). Bagged soil and mulch are sold by the litre, so the conversion tells you how many bags equal one bulk load.
- Check the volume printed on the bag, then divide 1000 litres by that number to find bags per cubic metre (indicative — check the label).
- Compare a bulk price per cubic metre with the bag price per litre, because the cheaper option depends on quantity and delivery.
- Remember that loose mulch settles, so a delivered cubic metre can look smaller after a few weeks.
- Soil volumes are measured loose, not compacted, so you may need more for firm, level beds.
- Ask the supplier whether the volume is loose or compacted before you order.
How much mulch do I need for my garden?
Use the same formula, but choose a depth that suits the mulch type. A thin layer of fine mulch works better than a thick layer of coarse mulch against weeds.
| Use | Typical depth | Cover per 1m3 mulch |
|---|---|---|
| Fine mulch in garden beds | 50 mm (indicative) | About 20 m² (indicative) |
| Coarse mulch around trees | 75 mm (indicative) | About 13 m² (indicative) |
| Thick weed-suppressing layer | 100 mm (indicative) | About 10 m² (indicative) |
These are arithmetic guides only, so check the mulch label and your plant needs.
Types of mulch: coarse mulch, wood chip and cedar
| Type | Best for | Notes |
|---|---|---|
| Coarse mulch | Large beds and trees | Slow to break down; keep it clear of trunks and walls |
| Wood chip mulch (Bunnings and nurseries) | Paths and shrub borders | Check the bag for the timber source and volume |
| Cedar mulch (Bunnings and nurseries) | Decorative beds | Check the label for the product details |
| Pine bark | Acid-loving plants and pots | See our guide on pine bark |
| Sugar cane mulch | Veggie gardens | Breaks down quickly and needs topping up |
| Coffee grounds | Compost and light top dressing | Use sparingly; see coffee grounds for plants |
How much top soil for lawn?
New lawns need a deeper layer than a top dressing on an existing lawn. Sandy loam suits most lawns, as explained in our sandy loam guide.
- For a new lawn, spread a layer of about 100 to 150 mm (indicative — check the turf supplier’s guide) before laying turf.
- For levelling an existing lawn, spread a thin layer of about 10 to 20 mm (indicative) and rake it in.
- Multiply your lawn area by the chosen depth to get cubic metres, then add a small buffer.
- Heavy clay in western Sydney benefits from added organic matter, so ask your supplier for a suitable blend.
- Turf laying costs about $17 to $46 per m² in Sydney, with $29 typical (October 2026), if you hire a professional.
How much soil do I need for raised beds and pots?
- Multiply length by width by depth in metres for a raised bed, then convert to litres.
- Fill the bottom with coarse material and top with quality mix, rather than using only fine soil.
- Allow extra soil because it settles after the first few waterings (indicative — ask your supplier).
- For pots, check the volume on the pot label and buy potting mix by the litre.
- Use a mix designed for the plant type, and follow the product label for feeding.
What affects the price
- Material type: cedar, pine bark and premium soils usually cost more than basic woodchip (indicative — ask your supplier).
- Bulk or bagged: a bulk load often costs less per litre but needs delivery space and access.
- Delivery: distance, truck size and driveway access can add to the bill.
- Labour: a Sydney gardener costs about $52 to $115 per hour, with $75 typical (October 2026).
- Access: steep sites, long carries and tight side gates slow the job down.
- Green waste: removing old mulch or soil adds time; see green waste removal cost and green waste disposal.
Cost by city
| City | What to compare | Note |
|---|---|---|
| Sydney | Bulk yards, Bunnings and nurseries | Garden clean-up costs about $170 to $460 per half day, with $290 typical (October 2026) |
| Melbourne | Local landscape suppliers | Prices vary (indicative — ask for a quote) |
| Brisbane | Local landscape suppliers | Prices vary (indicative — ask for a quote) |
| Perth | Local landscape suppliers | Sandy soils may need more organic matter (indicative — ask your supplier) |
| Adelaide | Local landscape suppliers | Prices vary (indicative — ask for a quote) |
DIY vs hiring a pro
| DIY | Hire a gardener |
|---|---|
| Lower cash cost for small beds | Saves time and effort on large areas |
| You control the depth and material | Handles heavy loads, edges and clean-up |
| Needs a wheelbarrow, shovel and rake | Brings tools and removes green waste |
| Heavy lifting risk | Safer for steep or awkward sites |
How to save without cutting corners
- Measure carefully before you order, so you do not pay for a second delivery or waste leftovers.
- Compare bulk and bagged prices per litre, including delivery.
- Reuse old mulch by raking and topping up, rather than stripping beds back.
- Use your own compost or council compost where it suits the bed.
- Combine mulching with a regular visit, such as garden maintenance, to save labour.
What a fair quote should include
- Itemised materials with volume and type listed, not a single lump sum.
- Delivery, spreading and levelling listed separately.
- Removal of old mulch or green waste.
- Clear access arrangements and tools used.
- Public liability insurance and a written scope of work.
FAQ: how much soil and mulch do I need
How much mulch do I need for my garden?
Measure the bed area, choose a depth, and multiply to find cubic metres. A shallow layer suits fine mulch, while coarse mulch needs more depth. Add a small allowance for settling, and keep mulch off trunks and walls.
How many litres in a cubic metre of soil?
A cubic metre holds 1000 litres (indicative — check the supplier’s measure). Divide that by the litre size printed on a bag to see how many bags equal one bulk load, and compare the price per litre.
How much soil do I need for a lawn?
For a new lawn, multiply the area by the soil depth recommended by the turf supplier (indicative — check the turf supplier’s guide). Add a small buffer. For levelling an existing lawn, a thin layer of top dressing is usually enough.
How much does 1m3 of mulch cover?
It depends on the depth you spread. As a rough guide, a cubic metre covers about 20 m² at 50 mm (indicative — check the supplier’s guide). Thicker layers cover less, so measure your bed before ordering.
Getting mulch and soil spread in Sydney
If you would rather skip the wheelbarrow, we spread mulch, tidy beds and remove green waste across Sydney. Book garden maintenance and mulching in Sydney and get an itemised quote. For better soil first, read our guide to how to improve garden soil, and see zeolite if you want a soil conditioner.
