Mulch Calculator
Work out mulch volume and the number of bags for a garden bed based on area and depth.
Set your values
Adjust the values, then calculate your result.
How to use Mulch Calculator
- Enter the measurements or amounts in the fields above.
- Check that dimensions, rates and units match the labels.
- Select “Calculate mulch” to see a clear estimate and the formula used.
How the mulch calculator works
Volume in litres = bed area × depth in centimetres × 10. Divide by bag size and round up to full bags.
Check your measurements and assumptions
Use the depth recommended for your mulch type and plants. Keep mulch clear of stems and building siding; this estimate does not account for settling or irregular bed edges.
Review the estimate before you act
Compare this result with an independent measurement, supplier quote or institution guidance when the decision matters. Confirm that the units and assumptions match the labels above, and update the inputs when the conditions change. Keep a note of the values used so you can reproduce the estimate later. This calculator is a planning aid and does not replace professional, product-specific or local guidance.
How deep should mulch be?
Depth depends on the material and planting situation. Enter the depth you plan to apply rather than treating this calculator as a gardening prescription.
Is input uploaded?
Processing takes place in your browser. This tool does not send your input or selected files to a conversion API.