Topsoil Calculator

Measured area (sq ft). Measure the ground surface receiving the soil layer. Exclude areas outside the work and divide major depth changes into separate calculations. This is a uniform-layer estimate, not a detailed grading takeoff.

Target finished soil depth (in). Enter the soil thickness you want remaining after the expected volume reduction. Measure the layer vertically from the existing surface to the intended finished surface. The calculator increases the loose volume when you enter settlement below.

Expected volume reduction after placement (%). Enter the percentage of the placed loose volume you expect to lose through settling or consolidation. For example, a 20% reduction means 80% of the loose volume remains. This is a project estimate, not a soil compaction specification; use appropriate supplier or project information.

Loose soil volume per bag (cu ft). Enter the loose soil volume listed on one bag, in cubic feet. The bag estimate uses the increased loose quantity, including the entered allowance. It is a purchasing alternative to the bulk-yard quantity, not an additional quantity.

Allowance (%). Enter the percentage you want to add for cutting, handling loss or other conditions specific to this work. Apply it to the measured quantity rather than enlarging the measurements as well. The suggested value is editable, not a universal recommendation; enter zero when no allowance is needed.

Loose depth is the layer needed before the entered volume reduction, so it can be greater than the target finished depth. Required cubic feet and cubic yards include the separate waste allowance. Bags round that loose volume upward. The fractional depth is a reference, not a grading or compaction specification.

Loose depth = target finished depth ÷ (1 − expected volume reduction ÷ 100). Loose cubic feet = area × loose depth ÷ 12 × waste factor. Divide by 27 for cubic yards or by bag volume and round up.

Worked example: 100 sq ft at 3 in finished depth with 20% volume reduction needs 3.75 in loose depth: 31.25 cu ft before waste. At 10% waste, 34.375 cu ft is 1.2731 cu yd or 35 one-cu-ft bags.

Uniform soil layer; settlement is a user-entered volume assumption, not a soil compaction specification. Existing soil, grading contours, moisture and supplier volume measurement affect quantity. Does not design structural fill or drainage.