📖Mulch, Soil & Gravel Guides

Every one of these questions starts the same way: you are standing at the edge of a bed, or in the aisle at the garden centre, holding a phone and trying to turn a tape-measure reading into a number of bags. The arithmetic is not hard. It is just that nobody writes it down in the order you actually need it.

These ten guides do that. They cover the volume formula that every landscape material shares, how deep mulch should actually go and what each extra inch costs, the point at which bulk delivery beats bagged, how many bags fit in a cubic yard for all five US bag sizes, what a yard of each material weighs and whether your truck can legally carry it, when to mulch and how often to replace it, how to fill a raised bed without buying twice the soil you need, the difference between topsoil, garden soil, compost and potting mix, how deep gravel goes under a driveway or patio, and a full density chart for converting cubic yards to tons.

Every number on these pages is either calculated here from the volume formula or taken from a cited university extension programme, the CPSC playground handbook or USDA NRCS. Nothing is rounded in a direction that helps a supplier.

If you want the number rather than the reasoning, start with the mulch calculator and come back here afterwards. The density and truck-load guide is the reference the rest of the site’s tools are built on.