Mulch & compost
Estimate compost volume for beds, borders and soil improvement. See equivalent units and every active assumption.
Enter project dimensions.
Calculated quantities for your project.
Enter measurements and calculate to see the result.
Direct answer
Calculate a compost volume for a defined layer or filled space. First decide whether compost is being used as a surface layer, a measured amendment or part of a planter mix, because each creates a different quantity.
Use separate calculations for top-dressing, new beds, containers and specified blend components. Do not replace a blend ratio with a general allowance percentage.
For a surface application, measure plan area and amendment depth. For a planter component, calculate the planter’s usable volume and apply only a specified blend proportion outside the tool.
Compost, soil conditioner, topsoil and growing media can have different compositions and uses. Supplier terminology and project requirements control selection.
A planting bed is triangular with an 8 m base and perpendicular height of 3.5 m. Its area is 8 × 3.5 ÷ 2 = 14 m². A specified 25 mm layer is 0.025 m, giving 14 × 0.025 = 0.35 m³.
The example uses geometry only. It does not insert a density, package size, recommended depth or supplier tolerance.
Check whether compost is sold in litres, cubic volume, bags or bulk loads and whether the named product is appropriate for the intended use. Package count needs the labelled capacity.
BulkMeasure does not create horticultural blend recipes, assess maturity or certify suitability. It calculates only the entered geometry.
Calculate the total space, then use only a professionally or supplier-specified proportion for each component.
Only for a mass estimate. Volume itself does not require density.
Review BulkMeasure’s calculation methodology, learn how to measure an area, and read about volume, density and estimated weight. Browse the calculator directory when another material or project better matches the job.