Raised Bed Soil Calculator
Fill volume for a raised bed. Enter inside dimensions and the height you’ll fill to — usually an inch or two below the top rail. Garden mix is the default; set settling to 10% if you plan to top it off.
Order 1.5 yd³ — bulk soil is sold by the ½ yard; most yards run a 3 yd³ delivery minimum.
- Area
- 32 ft²
- Volume (32.0 ft³)
- 1.19 yd³
- Weight @ 1.00 t/yd³
- ≈ 1.2 tons
- Waste / settling 10%
- + 0.12 yd³
- Order quantity
- 1.30 yd³
- Truckloads
- 1 × tandem dump (≈10 yd³)
- Metric
- 1.00 m³
- 40 lb bag (0.75 ft³)
- 47 bags
- 1 ft³ bag
- 36 bags
- 1.5 ft³ bag
- 24 bags
- Materials + delivery$20–$55 / yd³ · Aug 2026
- $105 – $158
- Installed (with labor)typ. $180
- $138 – $236
How to calculate topsoil by hand
Cubic feet = Length (ft) × Width (ft) × Fill height (in) ÷ 12 · Cubic yards = ft³ ÷ 27
Worked example
- Inside footprint: 8 ft × 4 ft = 32 ft².
- Fill volume: 32 ft² × (12 in ÷ 12) = 32 ft³ = 1.19 yd³.
- Settling 10%: 32 × 1.10 = 35.2 ft³ → 1.3 yd³ bulk, or 36 × 1 ft³ bags / 24 × 1.5 ft³ bags.
- 4 × 4 ft bed, 12″ deep
- 16 ft³ · 0.6 yd³
- 4 × 8 ft bed, 12″ deep
- 32 ft³ · 1.2 yd³
- 4 × 8 ft bed, 18″ deep
- 48 ft³ · 1.8 yd³
Questions crews ask
How much soil does a 4x8 raised bed need?
At 12 inches deep, 4 × 8 × 1 = 32 ft³ — about 1.2 cubic yards, or 32 one-cubic-foot bags. At 18 inches it is 48 ft³ (1.8 yd³). Buy 10% extra; the mix settles after the first watering.
What soil mix should I use for a raised bed?
A common recipe is 60% screened topsoil, 30% compost and 10% coarse material such as perlite or coarse sand. Many yards sell a pre-blended “garden mix” or “raised-bed mix” by the cubic yard that is cheaper than bags above about one yard.
Do I need to fill the whole depth with soil?
For beds deeper than 18″, fill the bottom third with logs, branches or coarse wood chips (hugelkultur) and top with soil. Enter only the soil depth in the calculator.