Raised Bed Soil Calculator
Use this raised bed soil calculator to estimate how much soil you need to fill your raised garden bed.
Enter the bed dimensions and depth to get cubic feet, cubic yards, and the number of 1 cubic foot bags.
Bed Shape
Results
Detailed Explanation
🎯 Purpose
This raised bed soil calculator helps you estimate how much soil you need to fill your raised garden bed. Raised beds are garden boxes elevated above ground level, typically filled with a mix of topsoil, compost, and other amendments.
📝 How to Use
1. Choose your bed shape (rectangle or circle). 2. Enter the length and width (or diameter) of your raised bed in feet. 3. Select the bed depth (8-18 inches is typical; 12 inches is the standard). 4. The calculator will show you the bed area, cubic feet of soil needed, cubic yards, and how many 1 cubic foot bags to buy.
🔢 Algorithm
For rectangle: Area = Length × Width For circle: Area = π × (Diameter ÷ 2)² Cubic Feet = (Area × Depth in inches) ÷ 12 Cubic Yards = Cubic Feet ÷ 27 Bags (1 cu ft each) = Round up to nearest whole number Tip: Most garden centers sell soil in 1 cubic foot bags, or you can buy bulk by the cubic yard.
💡 Why do it this way?
Why 12 inches depth for raised beds? - Too shallow (<8 inches): Plant roots can't grow deep, soil dries out fast in summer and freezes solid in winter, root development is poor. - Too deep (>18 inches): Wastes money on soil, and the lower layers don't breathe well — roots can rot. - 12 inches is the standard depth: Most vegetable roots reach 12 inches deep, and this depth lets roots develop fully without wasting soil. If you're growing deep-rooted plants (like tomatoes or carrots), go up to 15-18 inches. 📚 Sources: • USDA Raised Bed Guide: https://www.nrcs.usda.gov/ • Ohio State University Extension: https://extension.osu.edu/