Gardening Calculations: Soil, Spacing and Seeding
Plan a productive garden with confidence — how much soil to buy, how far apart to space plants and trees, how much seed and fertiliser you need, and the watering to keep it all thriving.
Garden Soil Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Soil needed
1.500
- In litres
- 1,500
- 50-litre bags
- 30
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Garden Soil Calculator
The Garden Soil Calculator works out your soil needed, along with 2 related figures in an instant. Enter length, width and depth and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the length.
- Enter the width.
- Enter the depth.
- Read off your soil needed, together with in litres and 50-litre bags — the calculator updates automatically, with no button to press.
Formula
The Garden Soil Calculator uses the formula:
Soil needed = Length × Width × (Depth ÷ 100)
Worked example
For example, with length of 5 m, width of 2 m and depth of 15 cm, the soil needed is 1.500.
| Length | 5 m |
|---|---|
| Width | 2 m |
| Depth | 15 cm |
| Soil needed | 1.500 |
|---|---|
| In litres | 1,500 |
| 50-litre bags | 30 |
Results are estimates for educational use, not professional advice.
Frequently asked questions
Multiply length × width × depth, with depth in metres. A 5 × 2 m bed at 15 cm deep needs 1.5 m³, about 30 fifty-litre bags.
There are 1000 litres in one cubic metre, which is how bagged soil and compost are usually sold.
10–15 cm suits most beds and lawns, while deep-rooted vegetables and raised beds may want 30 cm or more.
Yes. Soil settles and compacts, so adding about 10% extra avoids topping up later.
The Garden Soil Calculator uses the formula: Soil needed = Length × Width × (Depth ÷ 100). For example, with length of 5 m, width of 2 m and depth of 15 cm, the soil needed is 1.500.
Enter the length. Enter the width. Enter the depth. Read off your soil needed, together with in litres and 50-litre bags — the calculator updates automatically, with no button to press.
Related guides
Garden Soil Table: Soil needed by Length
Reference table of soil needed for Garden Soil across a range of length values — exact, engine-computed figures you can read off at a glance.
How to Calculate Garden Soil: Formula, Steps & Examples
Learn how to calculate Garden Soil — the formula explained step by step, with worked examples and a free calculator to check your answer.