Loam Calculator
Calculate cubic yards of loam (topsoil) needed for your project. Enter the area dimensions and target depth, get yardage, bag count, and cost estimate.
Reviewed & updated for 2026 by Rakesh Choudhary, PhDMethodology & sources · How we calculate
What loam actually is (and why it matters)
"Loam" gets used loosely at every landscape supplier, but in soil science it is a specific texture class: a mix of sand, silt and clay in which none of the three dominates. The USDA's soil texture triangle sets the exact percentage ranges. The proportions matter because each component does a different job.
- Sand creates large pore spaces. Water and roots move through them easily, but it doesn't hold moisture or nutrients.
- Silt has medium-sized particles that hold moisture and nutrients well. Pure silt is dense and compacts under foot traffic.
- Clay binds the mixture together, holds onto nutrients chemically, and retains water. Too much clay and the soil becomes a brick when it dries.
Loam hits the balance: drains well after rain, retains enough water that you don't have to irrigate daily, and holds the nutrients your plants release fertilizer or compost. This is why nearly every garden book, lawn product label, and county extension office recommends "loamy" soil. If you have heavy clay or sandy soil in your yard, amending it toward a loam composition is one of the highest-return projects you can do.
How much loam common projects need
Loam is sold by the cubic yard at most landscape suppliers. To know what to order, multiply your area in square feet by the depth in feet, then divide by 27. Here are some example projects; the sizes and depths are illustrations, and the volumes are computed from them:
| Project | Example size | Depth | Loam needed |
|---|---|---|---|
| New lawn (small yard) | 500 sq ft | 4 in | 6.2 yd³ |
| Lawn touch-up | 500 sq ft | 1 in | 1.5 yd³ |
| Vegetable garden bed | 100 sq ft | 8 in | 2.5 yd³ |
| Raised bed (4×8 box) | 32 sq ft | 12 in | 1.2 yd³ |
| Foundation planting strip | 200 sq ft | 6 in | 3.7 yd³ |
| Tree planting (single tree) | 4 ft × 4 ft | 18 in | 0.9 yd³ |
Order a little more than the bare volume. Loose loam settles once it is spread and watered, and you'll inevitably miscalculate a corner or want to top up a low spot. The calculator's order line adds 10%, a rule of thumb rather than a standard. Suppliers don't usually take returns for excess loam.
Bulk vs bagged: when each makes sense
Bulk loam usually costs less per yard than bagged, but bagged is more convenient for small jobs. Where the break-even falls depends on your local prices and the delivery charge.
| Factor | Bulk delivery | Bagged from store |
|---|---|---|
| Cost per yard | Supplier's price per yd³ + delivery | Bag price × 36 (0.75 ft³ bags) |
| Best for | Larger jobs, driveway access | Small jobs, backyard-only access |
| Delivery | Usually charged per trip | Carry yourself, or store delivery |
| Cleanup | Pile in driveway until used | Stack neatly, no mess |
| Screening quality | Pay extra for screened | Pre-screened by default |
To compare, multiply the price of a 0.75 ft³ bag by 36 and set that against the supplier's delivered price per yard. Bulk also has to reach the spot: think about whether a dump truck can get into your driveway.
FAQs
What is loam?
Loam is one of the soil texture classes: a blend of sand, silt and clay in which no single particle size takes over, so it drains yet still holds water and nutrients. Landscape suppliers often sell any screened topsoil as 'loam', so ask what is actually in the pile if the mix matters to you.
How much loam do I need?
Multiply length by width for the area in square feet, multiply by the depth in feet, and divide by 27 to get cubic yards. A 200 sq ft bed filled 3 inches deep: 200 × 0.25 = 50 cu ft, and 50 ÷ 27 = 1.85 cu yd. Round up when you order; the calculator's order line adds 10% as a rule of thumb.
How much does loam cost?
It depends on where you live, the quality (screened or not, amended with compost or not) and the season, and delivery is usually charged separately. Ask two or three local suppliers for a delivered price per cubic yard and type it into the price box; the calculator does not assume one.
How many cubic yards in a bag of topsoil?
Bags are sold by volume, and 0.75 cubic feet is a common size; check the label on yours. A cubic yard holds 27 cubic feet, so it takes 36 bags of 0.75 cu ft to make one yard and 72 bags to make two. At that point bulk delivery is usually worth pricing.
What depth of loam do I need for grass seed?
That depends on the soil you already have and what you are growing, so there is no single right number. Your state's cooperative extension service publishes lawn and garden advice for local soils; use its figure, or your landscaper's, as the depth in the calculator.
How heavy is a cubic yard of loam?
The calculator uses 2,000 lb per cubic yard, a typical trade figure for dry topsoil. Wet soil is much heavier, and the true weight varies with the mix, so ask the supplier for theirs before loading a pickup or trailer, and never go past the vehicle's rated payload.
Should I get screened or unscreened loam?
Screened loam has been sifted to remove rocks, sticks, and large debris. It usually costs more per yard but is easier to work with for lawns and gardens. Unscreened is fine for filling holes or grading areas where stones won't matter. For seeding or planting, get screened.