person using a tape measure to measure distance in garden

How Much Soil, Mulch or Turf Should I Buy? A Brisbane Bulk Materials Guide

How Much Soil, Mulch or Turf Do I Need? Your Brisbane Bulk Materials Guide

So, how much soil do I really need?

Ordering bulk landscaping materials for the first time can feel like guesswork.

Order too little and you're back in the ute for a second trip
Order too much and you've got a mound of soil going to waste.

The good news is the maths is simpler than it looks. This guide walks you through exactly how to measure your space and work out how many cubic metres of soil or mulch or square metres of turf you need for your Brisbane project, so you order the right amount the first time!

Use this link if you want to jump straight to a Soil & Mulch Online Calculator

Order the Right Amount of Soil & Mulch Calculator

What do I need to calculate Soil & Mulch?

Lets take a look at how to calculate and measure bulk landscaping materials. This is suitable if you are thinking of ordering the following:

What you're buying	What you need to measure	How it's sold
Soil, mulch, gravel, & sand	Length × width × depth	Cubic metres (m³)
Turf	Length × width / area	Square metres (m²)
Potting mix	Pot dimensions + fill depth	Litres or cubic metres

Measuring Bulk Materials

You might be asking: what is classed as a bulk landscaping material? Bulk landscaping products are often sold by landscaping supply stores and include:

When ordering bulk landscaping supplies, materials are sold by the cubic metre rather than by weight.

Selling by the cubic metre provides a more consistent way to measure bulk materials, as product weights can be affected by weather and moisture. For example, wet mulch weighs more than dry mulch.

Measuring materials by the cubic metre also makes sense for landscaping projects, as you often need to calculate garden beds, lawns and pots by volume anyway.

Bulk products that are sold by the cubic metre include decorative rocks, drainage gravels, mulch, sands, soils, potting mixes and compacting materials such as deco and crusher dust.

To work out how many cubic metres you need for your project, simply use this formula:

length × width × depth (in metres) = cubic metres.

For example: If you have a 4 m × 3 m garden bed and you want to add soil to a depth of 100 mm (0.1 m), you would need approximately 1.2 m³ of soil to fill the garden bed.

Calculation: 4 × 3 × 0.1 = 1.2 m³

Bulk material coverage cheat-sheet

As a quick guide, the amount of area 1 m³ will cover depends on how deep you want to spread the material.

Material / Depth	Approximate coverage per 1 m³
Soil at 100 mm deep	10 m²
Mulch at 75 mm deep	13m²
Mulch at 100 mm deep	10 m²
Decorative pebbles at 50 mm deep	20 m²
Gravel at 100 mm deep	10 m²
Sand at 50 mm deep	20 m²

These figures are approximate. The amount you need can vary depending on the material, the shape of the area and how evenly it is spread. For most landscaping projects, it's a good idea to allow a little extra rather than ordering exactly the calculated amount.

What if my garden bed isn't a rectangle?

Divide the area into smaller shapes. Calculate each section separately, then add the measurements together before multiplying by the required depth.

Laid turf and turf rolls placed on the ground

Measuring Turf

Turf is sold by the square metre (m²), so the first step is working out the total area of your lawn. This is usually straightforward for a simple rectangular lawn, but don't worry if your yard has curves, corners or an unusual shape you can break it down into smaller sections and calculate each one separately.

How to calculate your yard

Start by sketching out your yard and dividing it into simple shapes such as rectangles, triangles and circles. Measure each section, work out its area, then add all the areas together to get your total turf requirement.

Estimating by eye or stepping out the perimeter is not advised if you want an even finish.

These three formulas are all you need to work out your square meterage:

Rectangle: Length × Width = Area

Triangle: (Base × Height) ÷ 2 = Area

Circle: 3.14 × Radius × Radius = Area

Note: We recommend adding a 5% allowance to your total for odd corners and uneven spaces.

Want to calculate multiple materials, all in one place? Plan out your garden on our landscaping measurement page: Measurement Guide

How much potting mix do I need for my pots?

Working out how much potting mix you need for your pots can be confusing. You might be used to seeing potting mix sold in 20 kg bags or bags labelled by litres, while bulk potting mix is ordered by the cubic metre.

To make it easier to work out how much you need, we've put together the guide below.

How much potting mix should I buy?

The amount of potting mix you need to purchase depends on the size and shape of the potting vessel you're filling. For most pots and planters, you can work out the volume in litres and then convert this to cubic metres.

1 cubic metre (m³) = 1,000 litres

We also recommend allowing around 10% extra for settling and minor wastage. View Potting Mix Options.

Round pots

For a round pot, you'll need to know the diameter of the pot and the depth you want to fill it to. If you're purchasing a pot, take note of the dimensions or measure it with a tape measure. Remember to measure the depth from the bottom of the pot to the level where you want the potting mix to finish.

Once you have your measurements, use this formula to calculate your volume:

Volume in litres = π × radius² × fill depth ÷ 1,000

Note: The radius is just half the diameter.

For example, a 60 cm wide pot filled to a depth of 45 cm requires approximately 127 litres of potting mix.

Calculation: 3.14 × 30 × 30 × 45 ÷ 1,000 = 127 litres

Square and rectangular pots or planter boxes

For square or rectangular pots and planter boxes, the calculation is even easier. Simply measure the length, width and depth of your pot and then use the following formula:

Volume in litres = length × width × fill depth ÷ 1,000

Example: a rectangular planter box that is 100 cm long × 50 cm wide × 40 cm deep has a volume of approximately 200 litres of potting mix.

Calculation: 100 × 50 × 40 ÷ 1,000 = 200 litres

Volume in cubic metres (m3) = length × width × fill depth

Example: A rectangular planter box that is 100 cm long × 50 cm wide × 40 cm deep has a volume of approximately 0.2 m³ of potting mix.

Calculation: 100 × 50 × 40 ÷ 1,000,000 = 0.2 m³

Litres vs cubic metres

When you're buying potting mix in bulk, you'll often see quantities quoted in cubic metres (m³) rather than litres. If you know your volume in litres, converting this to a cubic metre measurement is simple.

1 m³ = 1,000 litres: So, if you have your measurement in litres, simply divide that by 1000 to get your m3 measurement.

Landscaping Supplies Measurement FAQS

1. How many wheelie bins in a cubic metre?

For a good visual representation of how much a cubic metre actually is, think of it in wheelie bins. One cubic metre of bulk landscaping material is equivalent to approximately 8 wheelie bins.

2. How much does a cubic metre of soil weigh?

As soil is an organic product, its weight can vary depending on the batch, moisture content and composition. The table below gives you a rough guide if you're trying to work out how much your truck or trailer could realistically hold.

Soil Type	Approx Weight
Dry, loose topsoil	1,100 to 1,300 kg/m³
Damp, loose topsoil	1,200 to 1,500 kg/m³
Wet, compacted topsoil	1,600 to 2,000 kg/m³
Compost / Organic mix	600 to 900 kg/m³
Clay-heavy soil	1,600 to 1,800 kg/m³

3. How much fits in your delivery trucks?

We have a range of delivery truck sizes to accommodate different access and manoeuvring requirements when delivering bulk materials. The maximum amount that one of our trucks can hold is 8 m³. For heavier items such as rocks, weight restrictions apply, so the maximum load may be less for these products.

4. How much will your courtesy trailer hold?

Our courtesy trailer has maximum load limits for different bulk landscaping supplies. These are outlined in the table below:

Product	Maximum Load
Sands	1/3 m3
Mulches	1 m3
Soils	1/3 m3
Composts	1/2 m3
Top Dress	1/3 m3
Gravels	1/3 m3
Rocks	1/3 m3
Concrete Blend	1/3 m3
Crusher Dust	1/3 m3
Deco	1/3 m3

5. Can I order less than 1m3?

Yes, we sell bulk materials in measurements of 1 m³, 1/2 m³, 1/3 m³ and 1/4 m³. On our online platform, we are currently only able to sell by 1 m³ and 1/3 m³. For other measurements, call our friendly staff on (07) 3245 5677.

6. What should I look into before I order?

Before placing your order, check:

Have you measured the length and width of the area?
Have you measured the depth you actually need?
Have you converted millimetres to metres?
Have you calculated the total area/volume rather than estimating?
Have you allowed for odd corners, trimming or settling where appropriate?
Are you ordering the correct unit — m² for turf or m³ for bulk materials?
Have you checked your vehicle or trailer's load capacity if collecting?

How to get it to your home?

Ordering bulk landscaping materials is one thing — getting them home and into the right spot is another. But with Rock N Soil, we make the process easy.

Whether you want us to handle the delivery or prefer to pick up the materials yourself, we have a range of options to suit your needs. You can be as involved as you like, or leave the heavy lifting to us.

Brisbane-wide bulk delivery service

Our large fleet of orange trucks delivers across Brisbane, the Redlands and beyond. With tipper trucks in a range of sizes, we can accommodate different site access requirements and transport split loads when needed.

Need your materials in a hurry? We can often offer same-day delivery when you order before 12 noon, making it a convenient option for those tricky last-minute landscaping jobs. Do you need more information for deliveries? Reach out to our friendly team: Landscaping Supplies Delivery Enquiries | Rock N Soil Delivery Information

Bulk Pick Up? Click and Collect Service

Prefer to pick up your materials yourself? If you have a suitable truck or trailer, our expert yardsmen can quickly and efficiently load your bulk materials for you.

Trailer Hire

Don't have a trailer but want to save on delivery fees? You can use our courtesy trailer for up to 3 hours free of charge. If you need it for the whole day, we also offer competitive hire rates after the initial 3 hours. Call us for more information on trailer hire 07 3245 5677.