Getting a useful estimate
Use the units your supplier quotes for delivery. Ask them whether the soil is suitable for your planting plan.
Measure the space you need to fill. Rectangles use length and width; circles use diameter. For several sections, choose combined areas and add rectangles, then subtract exclusions. The final area must be greater than zero.
Work out how much new soil is needed
Measure the space remaining to fill, rather than the full bed depth. If 2 inches of existing soil will stay in a 6-inch space, enter 4 inches. For uneven ground, calculate sections separately using each section’s remaining depth, then add their volumes.
A 20-by-15-foot area with 4 inches still to fill needs 100 cubic feet, or about 3.704 cubic yards before allowance. This is a quantity example, not advice on planting depth.
Check the quality of the soil you are buying
A topsoil label and dark color do not establish quality. Utah State University Extension recommends checking soil suitability before purchase and requesting tests when possible. Texture, pH, soluble salts, organic matter and coarse fragments can affect whether a load suits the site.
Ask where the soil came from, whether it is screened or blended, and what test results are available. Check for weed and herbicide history. If you are replacing usable soil, compare its test results with the proposed delivery before paying for new material.
Price the same product in bags and bulk
Compare the same soil specification in both quotes. Enter bag volume from the label; bag weight alone needs a product density. Include the bulk delivery charge and minimum order. The comparison shows full bags, the rounded bulk order and any surplus.
Volume formula
Allowance applies once to each volume layer. No density or compaction factor is assumed. If buying by weight, enter the density for your supplier’s product in the units shown.
Calculate a two-component blend
Use internal bed or container measurements and the remaining depth to fill. An optional blend divides the total between two components at percentages you supply. The percentages must total 100. Full bags round up and may leave extra material.
Sources & what they cover
- NIST SI conversion factorsNational Institute of Standards and Technology
Exact US customary and SI conversion factors; no material or installation recommendations.
Source checked - Topsoil Quality Guidelines for LandscapingUtah State University Extension
Purchasing topsoil: soil-test information, origin and quality checks. Regional guidance; no planting depth, nutrient prescription or soil blend imported.
Source checked
We check what each reference covers. A source check does not mean a specialist has reviewed this tool. You supply the depths, densities, prices and blend proportions.