Not sure how much to order? Use our calculator! This calculator will be best for rectangular or square shapes! Length of the area to be covered (in feet) Width of the area to be covered (in feet) How deep you want the soil, mulch or gravel to be (in inches) Calculate You need this many bags: Need more help? Here's some great tips! Each bag is 3′ by 3′ by 3′ and holds roughly one cubic yardOne cubic yard will hold 8 to 10 wheelbarrowsEach bag will cover an area that is 100 sq ft at 3 in deep