Soil Calculator
Enter your raised bed or planter dimensions to get the soil volume in cubic metres and litres, with bag equivalents for the common 25 L and 50 L sizes sold in Australian nurseries.
Enter your measurements
Your m³ of soil result will appear here instantly.
How to use this calculator
- 1
Measure the internal length and width of your raised bed or planter.
- 2
Enter the depth you want to fill — leave 2–3 cm below the rim of planter boxes so water doesn't overflow.
- 3
Compare the cubic metres against bulk delivery prices before you commit to bags.
- 4
For very deep beds over existing soil, consider filling the bottom third with cheap fill or garden rubble before the good soil.
- 5
Vegetable beds perform best with a quality garden blend or 50/50 soil-compost mix.
How the calculation works
Volume
Internal length × width × fill depth gives the volume in cubic metres. One cubic metre is 1,000 litres.
Bag equivalents
Nursery soil is typically sold in 25 L and 50 L bags. We divide your litre requirement by the bag size and round up to whole bags.
Worked example
A raised veggie bed 2.4 m × 1.2 m, filled to 40 cm deep.
Volume = 2.4 × 1.2 × 0.4 = 1.152 m³ ≈ 1,152 litres.
Order about 1.2 m³ of garden blend, or 24 × 50 L bags (48 × 25 L bags) if buying bagged.
Frequently asked questions
How much soil does a raised bed need?
It depends on what you're growing: 30–40 cm suits leafy greens, herbs and most vegetables; 40–50 cm gives root crops like carrots and parsnips room. Deeper beds need more soil but hold moisture better through Australian summers.
Should I fill the whole bed with premium soil?
You don't have to. For beds over about 40 cm deep, filling the bottom third with a cheaper bulk fill, coarse organic matter or even cleared garden rubble is common practice. Cap it with 25–30 cm of quality garden blend where the roots will live.
Why does delivered soil settle?
Bulk soil settles 10–20% over the first few weeks as it compacts and organic matter breaks down. If a bed looks low after a fortnight, that's normal — top it up rather than ordering generously the first time.
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Results are estimates only. Always confirm material requirements with your supplier or a qualified professional before purchasing.