How to Use the Rock'n'Soil Calculator
Ordering the right amount of turf and under turf is essential for a successful lawn installation — too little and you run short mid-job, too much and you're paying for product you'll never use. Our free turf calculator works out both in one step. Enter the length and width of your lawn area, set your desired under turf depth, and we'll instantly calculate the m² of turf and the m³ of under-turf blend you need to order.
You can enter measurements in metres, centimetres, millimetres, feet, or inches — whatever's on your plan or tape measure. For L-shaped lawns or yards with multiple zones, use the ‘Add another area’ button to add each section separately, and we'll sum the totals. We'll also apply a recommended 10% wastage allowance for offcuts and irregular edges.
How Turf Is Calculated - With Examples
Turf is sold by the square metre (m²). You calculate the area by multiplying the length by the width of your lawn. Under turf blend is sold by the cubic metre (m³), calculated as area × depth. Here are some real-world examples:
Small backyard (8×6m, 100mm under turf)
Average family lawn (12×10m, 120mm under turf)
Large lawn (20×15m, 150mm under turf)
Why Under Turf Depth Matters for Turf
The single most important factor in turf establishment is the quality and depth of the under turf layer. We recommend a minimum of 100mm of under-turf blend. In South East Queensland's clay-heavy soils, going to 150mm dramatically improves drainage and root penetration, meaning your new lawn establishes faster and survives dry spells better. Skimping on depth is the most common mistake in DIY lawn installations — our under-turf blends are specifically formulated to give new turf the best possible start.
Once you've checked your current soil type, browse our Queensland Turf Options tab for all currently available varieties — and pair them with an under turf product from the Under Turf Options tab. Under turf products can be delivered to Brisbane and The Redlands — same-day delivery may be available if ordered before 12pm, subject to availability. You can also collect from our depot by trailer.
