What is Soil?
The Soil Calculator estimates how much topsoil, garden soil, compost, or mulch you need for raised beds, garden plots, flower beds, and pots. Getting the right amount saves money (no over-buying) and trips to the store.
Raised beds are the most popular use case. A standard 4×4 foot raised bed that is 8 inches deep needs about 10.7 cubic feet of soil — approximately 11 bags of 1 cubic foot soil mix. A common raised bed recipe is 60% topsoil, 30% compost, and 10% perlite or vermiculite.
For large projects, buying soil by the cubic yard is more economical. One cubic yard = 27 cubic feet, which fills a raised bed approximately 4×8 feet at 12 inches deep.
Formula
Volume = Length × Width × Depth (converted to same units)
Cubic Feet = Length(ft) × Width(ft) × Depth(inches)/12 Cubic Yards = Cubic Feet / 27 Bags = Cubic Feet (1 bag ≈ 1 cubic foot) Liters = Cubic Feet × 28.317
Example — 4ft × 4ft raised bed, 8" deep: Volume = 4 × 4 × (8/12) = 10.67 cubic feet = 0.40 cubic yards = 11 bags = 302 liters
How to use this Soil Calculator?
1. Enter bed length and width in feet. 2. Enter soil depth in inches (8-12" is typical for raised beds). 3. See volume in cubic feet, cubic yards, number of bags, and liters.