Interactive Topsoil calculator
Estimated result
Enter measurements and select Calculate.
How to use this calculator
- Use a direct area when a survey or plan already provides it.
- Otherwise measure a representative rectangle or divide an irregular bed into sections.
- Enter the desired finished soil depth.
- For bags, copy the bag volume exactly from the label.
Formula and method
Topsoil volume = area × finished depth. The selected allowance increases the planned volume. Bag count = adjusted cubic feet ÷ entered bag volume, rounded up.
Worked example
A 12 ft by 8 ft bed filled 6 in deep contains 48 ft³, or about 1.78 yd³ before settling allowance.
Assumptions and result interpretation
- No universal topsoil bag size is assumed.
- Bulk density changes with texture, organic matter, moisture, and compaction, so this page estimates volume rather than shipment weight.
- A settling allowance is optional and should reflect the product and installation method.
Common mistakes
- Entering bag weight instead of bag volume
- Using inches without choosing inches
- Ignoring existing soil already in the bed
- Treating a volume estimate as a guaranteed delivered weight
Methodology sources
Conversions use deterministic factors. Variable material properties are either visibly sourced and editable or left for the user to enter from the supplier.
Results are planning estimates. Confirm actual requirements with the appropriate supplier, contractor, engineer, building official, or other qualified professional.