Soil calculator for Idaho
Determine the cubic yards needed for garden beds, raised planters, and other outdoor work, using soil matched to the application.
Enter your project dimensions
At 12 inches deep, a 4 x 8 raised bed requires 32 cubic feet of soil. That equals 1.2 cubic yards, more material than many new bed builders anticipate when planning for a few bags. Use this calculator for any bed, planter, or landscape area and select the soil type for an accurate tonnage. Garden soil weighs about 2,000 lb per cubic yard, screened topsoil 2,200, and fill dirt 2,400.
Three steps for bed calculations
- Record every bed or planter's dimensions in feet. Multiple-areas mode adds the separate entries together.
- Choose depth for the intended use: 4-6 inches for existing-bed improvement, 6 inches for a new in-ground bed, and 12 inches to fill an empty raised planter.
- Divide cubic feet by 27 for cubic yards. Then multiply yards by 1.0 to 1.2 for tons, based on soil type.
Tons = yards × 1.0 (garden soil) · 1.1 (topsoil) · 1.2 (fill dirt)
Coverage and weights
| Soil type | Weight per cubic yard | Tons per yard |
|---|---|---|
| Garden soil (blended with compost) | ≈ 2,000 lb | 1.00 |
| Topsoil (screened) | ≈ 2,200 lb | 1.10 |
| Fill dirt | ≈ 2,400 lb | 1.20 |
| Depth | 1 cubic yard covers | 3 yards cover |
|---|---|---|
| 2 inches | 162 sq ft | 486 sq ft |
| 4 inches | 81 sq ft | 243 sq ft |
| 6 inches | 54 sq ft | 162 sq ft |
| 12 inches, raised bed | 27 sq ft | 81 sq ft |
Choose soil for the work
- For vegetable plots, flower beds, and containers, select garden soil blended with compost and prepared for planting.
- Use screened topsoil for lawn work and final grade shaping. The Topsoil Calculator provides lawn depths and sample calculations.
- For backfilling holes or changing grades, use fill dirt below and reserve growing soil for the top layer.
- Rather than replacing an entire bed with worn native soil, mix 2-3 inches of garden soil into its upper 6 inches. This uses less material and creates a more gradual rooting zone.
Filling deep raised beds economically
For beds higher than 18 inches, reserve the garden soil for the root zone instead of filling the full depth with it. Place fill dirt or coarse organic material that will break down in the lower layer, then finish with 8-12 inches of garden soil above. Run the calculator once for each layer. Raised-bed planning picks up in April, so measure the 12 inches rather than estimating it.
Example calculation: three 4 x 8 beds
A bed measuring Ninety-six square feet at 12 inches deep contains 96 cubic feet, equal to 3.6 cubic yards and about 3.6 tons of garden soil. Order 4 yards. Blended soil can settle roughly 10% during the first weeks as compost consolidates, leaving extra material for refilling the beds afterward.
Improving clay and sand in place
Clay holds water too long, while sandy ground can dry out between irrigations. For either condition, work 2-3 inches of compost-blended garden soil into the upper 6 inches and repeat for a couple of seasons. This uses a third of the material required for replacing the bed in full. Consider full-depth replacement only where debris or contamination excludes the native soil.
Bulk soil compared with bags
One cubic yard is roughly 36 bags at 40 lb each. A single raised bed can take 43 bags, and loading 43 bags twice is a lot of lifting. Bulk material costs less by the cubic foot and is delivered in one tip, with free delivery included. Bags are useful for refreshing one planter. Have the pile placed on a tarp: soil can mark concrete, while a tarp makes cleanup a matter of dragging and folding it.
Soil amounts for beds and bags
How much soil is needed for a 4x8 raised bed?
How do garden soil, topsoil, and fill dirt differ?
How many bags equal one cubic yard of soil?
How many yards of dirt are required for beds?
Will bulk soil settle after placement?
Can delivered garden soil be planted in directly?
More calculators
Beds measured? Order soil online.
Order garden soil, topsoil, or fill dirt by the yard, with free delivery included.
