The Raised Bed Soil & Compost Sizer calculates the exact cubic feet, bulk cubic yards, and commercial retail bags needed to fill garden raised beds and planter boxes.

### Mathematical Volume & Material Split Formulas Raised planter beds require calculating rectangular solid volume and converting between loose bulk units and retail bagged measurements: - Soil Depth in Feet: $$\text{Depth}_{\text{ft}} = \frac{\text{Bed Depth (inches)}}{12}$$ - Total Bed Volume (Cubic Feet): $$\text{Volume}_{\text{cu ft}} = \text{Length (ft)} \times \text{Width (ft)} \times \text{Depth}_{\text{ft}}$$ - Bulk Volume (Cubic Yards): Standard bulk landscape deliveries are priced by the cubic yard ($1\text{ cu yd} = 27\text{ cu ft}$): $$\text{Volume}_{\text{cu yd}} = \frac{\text{Volume}_{\text{cu ft}}}{27}$$ - Bagged Retail Splits (1.5 cu ft Bags): $$\text{Total Bags} = \left\lceil \frac{\text{Volume}_{\text{cu ft}}}{1.5} \right\rceil$$ $$\text{Compost Bags} = \left\lceil \frac{\text{Volume}_{\text{cu ft}} \times (\text{Compost Ratio}\% / 100)}{1.5} \right\rceil$$ $$\text{Topsoil Bags} = \text{Total Bags} - \text{Compost Bags}$$

### Worked Gardening Example Consider constructing a standard vegetable bed: **8 feet long**, **4 feet wide**, and **12 inches deep**, using a **30% compost blend**: 1. **Total Bed Volume**: $$8 \times 4 \times \left(\frac{12}{12}\right) = 32.0\text{ cubic feet}$$ 2. **Bulk Cubic Yards**: $$\frac{32.0}{27} \approx 1.19\text{ cubic yards}$$ 3. **Retail 1.5 cu ft Bag Count**: $$\text{Total Bags} = \left\lceil \frac{32.0}{1.5} \right\rceil = \lceil 21.33 \rceil = 22\text{ bags}$$ 4. **Soil vs. Compost Split**: - Compost Volume (30%): $32.0 \times 0.30 = 9.6\text{ cu ft} \to \lceil 9.6 / 1.5 \rceil = 7\text{ bags compost}$ - Topsoil Volume: $22 - 7 = 15\text{ bags topsoil or raised bed base mix}$

> Landscaping Tip: Soil settling naturally reduces initial bed height by 10% to 15% after thorough saturation. Ordering or bagging the rounded-up figure prevents sunken soil lines.

### Private In-Browser Calculation All garden bed dimensions, volume conversions, and bag calculations run locally in your web browser. No measurements are stored or sent across the network.