Home Materials Soils Soil Compost Mix Soil Compost Mix$50.00 local delivery$40 picked-up 50/50 compost/topsoil mix. Soil Compost Mix quantity Add to cart How much should you order? Use this calculator to find out how much material you need for your project. Length (in feet) Width (in feet) Depth (in inches): Materials for sale by the ton or cubic yard. The coverage per unit is 90-110 square feet at a depth of 2 or 3 inches.