Gravel & Mulch Calculator
Calculate the volume and bags of gravel, mulch, topsoil or sand needed.
Assumptions used in this calculation
- Bag sizes: Uses typical bag sizes per material (0.5 cu ft for gravel/sand, 2 cu ft for mulch, 1.5 cu ft for topsoil), actual bag sizes vary by brand.
About this calculator
Buying loose landscaping material by eyeballing a pile at the garden centre almost always ends in a second trip or leftover bags stacked in the garage, because the volume math, area times depth converted into cubic yards, then into bags, is easy to get wrong without doing it on paper first. This calculator takes the area you want to cover and your target depth, converts that into cubic yards, then divides by a typical bag size for gravel, mulch, sand or topsoil to give you a ready-to-buy bag count alongside the raw volume. Because each material comes in a different standard bag size, denser materials like gravel and sand in smaller bags, lighter mulch in larger ones, entering the same area and depth for different materials produces very different bag totals, which is exactly the kind of detail that's easy to miss doing the math by hand. Adjust depth to match the material: shallower for mulch, deeper for structural gravel bases.
Worked example
200 sqft, 3in depth, gravel
Result: ≈ 1.85 cubic yards, 100 bags
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