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.
Raised Bed Soil Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Soil needed
32.00
- Cubic yards
- 1.185
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Raised Bed Soil Calculator
The Raised Bed Soil Calculator works out your soil needed, along with 1 related figure in an instant. Enter length, width and fill 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 fill depth.
- Read off your soil needed, together with cubic yards — the calculator updates automatically, with no button to press.
Formula
The Raised Bed Soil Calculator uses the formula:
Soil needed = Length × Width × (Fill depth ÷ 12)
Worked example
For example, with length of 8 ft, width of 4 ft and fill depth of 12 in, the soil needed is 32.00.
| Length | 8 ft |
|---|---|
| Width | 4 ft |
| Fill depth | 12 in |
| Soil needed | 32.00 |
|---|---|
| Cubic yards | 1.185 |
Results are estimates for educational use, not professional advice.
Frequently asked questions
Multiply length × width × fill depth in feet. An 8 × 4 ft bed filled 12 inches deep needs 32 cubic feet of soil.
A common raised-bed mix is roughly equal parts topsoil, compost and aeration material like coarse sand or perlite.
8–12 inches suits most vegetables. Deep-rooted crops like carrots and tomatoes appreciate the deeper end.
Yes, over the first season. Top up with compost each year as the level drops and nutrients are used.
The Raised Bed Soil Calculator uses the formula: Soil needed = Length × Width × (Fill depth ÷ 12). For example, with length of 8 ft, width of 4 ft and fill depth of 12 in, the soil needed is 32.00.
Enter the length. Enter the width. Enter the fill depth. Read off your soil needed, together with cubic yards — the calculator updates automatically, with no button to press.
Related guides
Raised Bed Soil Table: Soil needed by Length
Reference table of soil needed for Raised Bed Soil across a range of length values — exact, engine-computed figures you can read off at a glance.
How to Calculate Raised Bed Soil: Formula, Steps & Examples
Learn how to calculate Raised Bed Soil — the formula explained step by step, with worked examples and a free calculator to check your answer.