Mulch Calculator
Mulch is light for its bulk — about 25 lb per cubic foot, a quarter of topsoil.
Volume to order1.8519 cubic yards50 cu ft · 1.4158 m³
Weight0.6243 US tons566.3 kg · 1,248.6 lb · 0.5663 tonnes
MaterialMulch400 kg/m³, about 25 lb/ft³, varies widely
Cubic feet50
Cubic metres1.4158
In 50 lb bags25if buying bagged rather than bulk
Area covered200 sq ft18.5806 m²
Depth3 in76.2 mm
One cubic yard covers108 sq ftat 3 in deep
The method
volume = area × depth; weight = volume × density
Depth in inches, volume in yards
This is where the arithmetic usually goes wrong. A cubic yard is 27 cubic feet, so spread 4 inches deep it covers 81 square feet — not 27. Divide the depth in inches by 12 before multiplying, or work in a single unit throughout.
Order by volume when you can and treat the weight as a cross-check. Loose densities vary by about 10% between quarries and rise sharply when the material is wet, so a ton of gravel is a less definite quantity than a cubic yard of it.
Add a compaction allowance for anything that will be rolled or tamped. Crusher run and road base typically lose 20–25% of their loose volume once compacted.