Soil calculator for Wyoming

A 4 x 8 raised bed at 12 inches deep needs 32 cubic feet of soil, which works out to 1.2 cubic yards. That amount often catches new bed builders off guard when they planned on buying only a few bags. This calculator figures quantities for beds, planters, and yard work using the three available soil types. Blend affects weight: garden soil weighs about 2,000 lb per cubic yard, screened topsoil 2,200, and fill dirt 2,400. Select the material you plan to order so the ton calculation matches.

Three steps for bed calculations

1. For every bed or planter, note the measurements in feet. Multiple-areas mode adds all beds into one total.
2. Choose depth by purpose: add 4-6 inches to improve existing beds, use 6 inches for new in-ground beds, and allow 12 inches to fill an empty raised planter.
3. For cubic yards, divide cubic feet by 27. Multiply yards by 1.0 to 1.2 to find tons according to soil type.

Coverage and weight

Choose soil for the work

• For vegetable gardens, flower beds, and planters, use garden soil blended with compost and prepared for planting.
• Screened topsoil works for lawn finishing and final grading. Find lawn depth guidance and examples in the Topsoil Calculator.
• For filling holes or changing grades, place fill dirt below and reserve growing soil for the top layer.
• Rather than replace a whole bed of tired native ground, work 2-3 inches of garden soil through the upper 6 inches. It uses less material, and roots can get established more easily.

Fill raised beds for less

You do not need costly blended material through the full depth of a tall bed. Above 18 inches, make the lower third from fill dirt or coarse organic matter that decomposes in place, then reserve 8-12 inches of garden soil for the root zone. Calculate each layer separately with two runs. Raised-bed work often starts in April, so measure the full 12 inches rather than estimating depth.

Example: three 4 x 8 beds

For Ninety-six square feet filled to 12 inches, you need 96 cubic feet, which works out to 3.6 cubic yards or about 3.6 tons of garden soil. Order 4 yards. During the first weeks, the compost portion can consolidate and settle roughly 10%, leaving the extra material to refill the beds afterward.

Improve clay and sand in place

Clay can stay wet for too long, while sandy ground can drain before plants have time to use the water. Treat both by tilling 2-3 inches of compost-blended garden soil into the upper 6 inches, then repeating over a couple of seasons. That takes a third of the material and lifting needed for full replacement, while roots and worms gradually carry the blend deeper. Use full-depth replacement only where construction debris or contamination makes the native soil unsuitable.

Bulk soil or bagged soil

One cubic yard is about 36 bags at 40 lb apiece. A single raised bed can require 43 bags, and hauling 43 bags twice is no fun. Bulk material costs less per cubic foot, comes in one tipped load, and free delivery means no truck fee to make up. Bags still make sense for topping off one planter. Have the pile placed on a tarp since soil can stain concrete, then drag and fold the tarp for cleanup.

Soil amounts for beds and bags

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