Gravel Soil Mulch Calculator (Cubic Yards)

Same rectangle as a slab, but you usually buy by the cubic yard or cubic metre. Depth is the finished thickness; the waste / compaction percent adds what edges, settling and compaction take.

Inputs

Units

Results

Volume: 55.00ft³
Volume: 2.037yd³

The Result is indicative and educational. It does not constitute a design, a technical opinion or medical advice and does not replace calculations or verification by a person with the appropriate qualifications and authorisations. Before purchase, installation or use in practice – in particular in electrical installations – the Result should be verified by a qualified specialist. Details: Terms of Service, point 4.

Example products

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Calculation method

A 20×10 ft bed 3 in deep is 50 ft³ (1.85 yd³) before waste; with 10% extra it is 55 ft³ (2.04 yd³). Ten percent covers irregular edges and the settling of loose mulch or gravel; for a base you compact with a plate compactor, use 15–25%. Metric mode reports m³ of the same pile: a 6 × 3 m bed 75 mm deep with 10% extra is 1.485 m³.

Exact formula

cu ft = L × W × (depth_in / 12) × (1 + waste/100). cu yd = cu ft / 27.

Irregular beds

Split a kidney-shaped bed into rectangles and add the volumes, or average width × length.

Frequently asked questions

How deep should mulch be?

2–3 in (50–75 mm) is typical. Deeper mulch can smother plants.

How many bags of mulch or soil?

Divide the volume by the bag size and round up. US bags are usually 2 or 3 ft³, so 55 ft³ is 28 bags of 2 ft³. Metric bags are sold in litres and 1 m³ is 1000 L, so 1.485 m³ is 22 bags of 70 L.

Gravel for a driveway?

Build it in compacted layers of about 4 in (100 mm) and enter each layer separately if the stone sizes differ. This rectangle is the volume, not a pavement design.

Cubic yards vs tons?

Yards are volume. Tons need the bulk density from the supplier: gravel is often about 1.4 US tons per cubic yard, roughly 1.5–1.8 t/m³. This tool stays on volume.