Topsoil & Mulch Calculator — ft, yd³, bags
How to use this calculator
Pick the bed shape — rectangle, circle, L-shape, or a known square-footage — and enter dimensions in feet and inches. Choose the material, set spread depth, and add a waste allowance for uneven subgrade and settling. Loose-delivered material is sold by the cubic yard (1 yd³ = 27 ft³); bagged products are sold by ft³ or in 1 yd³ bulk totes.
Depth drives quantity far more than footprint: doubling depth doubles volume. Spread bark or wood mulch 2–3″ for beds and up to 4–6″ for weed suppression; lay screened topsoil 4–6″ for new turf and 8–12″ for raised garden beds. Bulk topsoil is loose-measured, so order roughly 10–15% over the geometric volume to cover spreading loss and minor compaction. For excavating an existing bed first, size the dig with the excavation volume calculator and balance haul-off against import using cut and fill.
Saved Calculations
| Time | Shape | Material | Area ft² | Vol yd³ | Bags | Weight | Cost |
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How to Calculate Topsoil & Mulch
Soil and mulch are sold loose-measured by the cubic yard, so the practical workflow is: measure the bed footprint, decide a finished spread depth, convert to cubic yards, then pad for spreading loss and settling. The waste slider defaults to 5% for flat, clean ground and should be raised to 10–15% for sloped or irregular beds where material rolls and over-spreads at the edges. Bag counts round up — partial bags are never sold.
Formulas
Volume = Area × Depth. Rectangle Area = L × W; Circle Area = π × (Diameter ÷ 2)²; L-shape = (A × B) − (C × D). Cubic yards = ft³ ÷ 27. Bags = ⌈ft³ ÷ bag ft³⌉. Weight = yd³ × density (lb/yd³). Truck loads = yd³ ÷ 10 (typical tandem dump body). A waste factor w is applied as Volume × (1 + w).
Material Densities
Densities are loose, as-delivered approximations and vary with moisture: topsoil ≈ 2,000 lb/yd³ (≈ 1.0 ton) · garden soil ≈ 1,800 · compost ≈ 1,000 · wood-chip mulch ≈ 600 · bark mulch ≈ 500 · rubber mulch ≈ 1,200 · peat moss ≈ 400 · fill sand ≈ 2,700 lb/yd³. Wet topsoil can weigh 20–30% more, which matters for delivery truck capacity.
FAQ
How deep should I apply mulch? 2–3″ for flower beds, 3–4″ for pathways, up to 6″ for weed suppression. How deep for topsoil? 4–6″ for new lawns, 8–12″ for garden beds. Bulk or bags? Above about 2 yd³, loose bulk delivery is usually cheaper per yard than bags despite delivery fees. Why is delivered volume more than I calculated? Bulk soil is sold loose and swells 20–30% over compacted bank volume, so always include the waste allowance. For aggregate base under a path use the gravel & aggregate calculator; for backfilling around new work see the fill & backfill calculator, and for footing soil to be placed back see the concrete pier calculator.
Ordering tips
In 2025 USA, bagged hardwood or bark mulch runs $4–7 per 2 ft³ bag at big-box retail; bulk loose mulch is $25–45/yd³ delivered. Screened topsoil is $25–55/yd³ delivered, garden-blend soil $35–70/yd³. The most common over-order mistake is forgetting that loose-measured bulk soil settles: 4″ of fresh topsoil shrinks to about 3–3¼″ after one rain, so order with the compacted-depth checkbox on for new lawns and driveway base. Delivery fees commonly start at $75–150 within ~10 miles, so combine deliveries when possible. Aged or double-shredded hardwood mulch holds color better than fresh wood chips and is preferred for visible front-yard beds; raw wood chips and arborist chips are fine for path or playground use and are often free from local tree services. Most municipalities limit soil import on flood-zone or wetland parcels — check local grading rules before raising more than a few inches over a property line.
