Do not mix component mass ratios with soil volume ratios.
Does an equal mass blend also provide equal component volumes?
Use the matching calculator
Use this decision sequence
- Read the specified blend basis: volume parts or weight parts.
- Use the volume-blend tool only for an explicitly supplied volume ratio.
- Keep each component’s actual bag volume or mass on that same basis.
- Round components separately without changing the specified proportions at the theoretical-need stage.
Keep the quantities distinct
| Quantity or assumption | How to use it |
|---|---|
| Volume ratio | Splits the target prepared volume. |
| Mass ratio | Requires a different quantity basis. |
| Bag rounding | Changes purchased amounts, not the specified theoretical blend. |
Worked comparison
An illustrative volume blend with two parts A and one part B across 0.3 m³ needs 0.2 m³ A and 0.1 m³ B before separate bag rounding. If the components have different densities, their mass shares are not automatically two to one. A correct total bag count cannot resolve a ratio whose basis was never specified.
Check before using the estimate
The ratio is supplied; no soil recipe, growing performance or material suitability is recommended.
All dimensions, product properties, prices and specifications in this example are illustrative arithmetic inputs. Use the values from your measured plan, selected product data sheet and supplier quote. This guide does not choose construction specifications or certify safety.
Calculation and scope checked 2026-10-04. Methods and scope.