Garden · Garden
How Much Soil Does a Raised Bed Need?
Use internal bed dimensions, not outside lumber dimensions, and separate soil volume from mulch volume.
Measure the inside
Record the actual planting volume after boards, liners and structural members are installed.
Convert depth carefully
A 12-inch depth is one foot; 6 inches is half a foot. Small depth errors multiply across a large bed.
Allow for settling
Bag labels and bulk deliveries are volume estimates. Soil may settle after watering and filling.
Keep amendments separate
Compost, topsoil and specialty media may be mixed by ratio rather than treated as one interchangeable material.
Use the calculator
Start with the soil calculator, then verify bag or bulk-yard quantities against the supplier.