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 |
|---|
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
Geometric volume = area × depth. Net cubic yards = ft³ / 27. If the entered depth is a compacted/settled target, loose pre-waste volume = net / (1 − entered shrink); otherwise the multiplier is 1. Order volume = pre-waste volume × (1 + waste). Bags = ceil(order ft³ / entered bag ft³). Weight = order LCY × entered loose lb/LCY.
Loads by volume = ceil(order LCY / entered LCY per load). Loads by payload = ceil(order short tons / entered tons per load). Governing whole loads = max(volume loads, payload loads).
Material Densities
The material selector provides representative starting values only. Loose bulk density varies substantially with moisture, screening, organic content and supplier; edit the density using supplier or measured data before relying on weight or payload-limited delivery counts.
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.
Calculation notesWhat this calculator doesOpen the formula basis, references and assumptions when you need to verify the detailed method.Review details
Area and depth are converted to cubic yards and bag counts using selected product coverage, waste and whole-package rounding.
Reference context
- • geometric volume relationships
- • project geotechnical information
- • supplier density and compaction data
Important assumptions
- • Dimensions, quantities and prices entered by the user are correct.
- • Waste, laps, overlaps, compaction and delivery allowances must match the actual project.
- • Results are preliminary takeoff estimates, not a sealed structural design or permit approval.
Quality notes updated: August 1, 2026. The repository includes per-page checks for browser errors, populated results, metadata, US-market visibility, duplicate IDs and shared quality controls.
Reference names describe the applicable design and product context; they do not replace a project-specific code review. Local codes, drawings, specifications and manufacturer instructions govern the final work. Report a calculation or interface issue.
