Home Materials Soils Compost Compost$50.00 local delivery$40 picked-up Mushroom compost. Compost 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.