Mulch & soil calculator
For garden beds, raised beds, and top-dressing a lawn. Works for mulch, topsoil, or compost — just change the depth and bag size.
Bed details
How this is calculated
Volume is bed area times depth, with depth converted from inches to feet: length × width × (depth ÷ 12). That gives cubic feet. A 10% margin is added on top for settling — loose mulch and soil compact over the first few weeks, so a little extra keeps beds looking full into the season. Cubic feet is divided by 27 to get cubic yards, which is how bulk suppliers price and deliver. For bagged material, the same cubic footage (with the margin included) is divided by the bag's volume and rounded up.
How much mulch for a 10×4 bed?
At the standard 3" depth, that bed needs about 0.4 cubic yards, or roughly 6 bags of 2 cu ft mulch.
Bagged or bulk — which is cheaper?
Bulk mulch or soil by the cubic yard is almost always cheaper once you need more than about 3–4 bags worth, but it usually requires a truck bed or trailer to haul, plus somewhere to dump and shovel from.
How deep should mulch actually be?
2–3 inches is enough to suppress weeds and retain moisture without smothering roots. Piling mulch deeper than 4 inches, especially against a trunk or stems, can trap moisture and invite rot.
Once you know how much to order
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Garden fork & wheelbarrow
Makes spreading bulk mulch or soil far less brutal.
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