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, PhD · How we calculate
What loam actually is (and why it matters)
"Loam" gets used loosely at every landscape supplier, but in soil science it has a specific definition. Loam is a soil mixture with roughly 40% sand, 40% silt, and 20% clay. 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's what typical residential projects look like:
| Project | Typical size | Depth | Loam needed |
|---|---|---|---|
| New lawn (small yard) | 500 sq ft | 4 in | ~6 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 deep | ~0.9 yd³ |
Always order 10 to 15% more than the calculator says. Loam settles by 10-20% within a few weeks of being laid down, and you'll inevitably miscalculate a corner or want to top up a low spot. Suppliers don't usually take returns for excess loam.
Bulk vs bagged: when each makes sense
Bulk loam is dramatically cheaper per yard than bagged, but bagged is more convenient for small jobs. The break-even point is usually around 1 cubic yard.
| Factor | Bulk delivery | Bagged from store |
|---|---|---|
| Cost per yard | $25-$70 + delivery | $130-$180 effective |
| Best for | 2+ yards, driveway access | Under 1 yard, backyard-only access |
| Delivery | $50-$150 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 |
A practical rule: if your project needs 2 yards or more, get bulk delivery — you'll save $100-$300 and be done in one trip. Under 1 yard? Stick with bags. Between 1 and 2 yards is a judgment call based on whether you can fit a dump truck in your driveway.
FAQs
What is loam?
Loam is a soil mixture of roughly 40% sand, 40% silt, and 20% clay, considered the ideal soil for most plants. It drains well, retains moisture, and is rich in nutrients. 'Loam' is often used interchangeably with 'topsoil' in landscaping contexts, though true loam is a specific composition.
How much loam do I need?
Calculate volume: length × width × depth, then convert to cubic yards (1 cu yd = 27 cu ft). For a 200 sq ft area at 3 inches depth: 200 × 0.25 = 50 cu ft = 1.85 cu yd. Round up to 2 cu yd. Add 5-10% extra for settling and compaction.
How much does loam cost?
Bulk loam from a landscape supplier: $25-$70 per cubic yard (varies by region and quality). Premium screened loam: $50-$100/yd. Delivery typically $50-$150 per trip within local range. Bagged topsoil from home stores: $3-$5 per 0.75 cu ft bag (much more expensive per yard but convenient for small jobs).
How many cubic yards in a bag of topsoil?
Standard topsoil bags are 0.75 cubic feet. 1 cubic yard = 27 cubic feet = 36 bags. For a typical lawn project needing 2 cubic yards, you'd need ~72 bags or buy bulk delivery. Bulk is usually cheaper per yard once you need more than 1 cubic yard.
What depth of loam do I need for grass seed?
For new lawn installation: 4-6 inches of loam on top of existing soil. For overseeding/touch-ups: 1-2 inches. For garden beds: 6-12 inches depending on plants. For raised beds: fill entirely (12-18 inches typically).
How heavy is a cubic yard of loam?
1 cubic yard of loam weighs approximately 1,800-2,200 lbs (about 1 ton), depending on moisture content. Dry loam is lighter; saturated/wet loam can exceed 2,500 lbs per cubic yard. A standard pickup truck can typically carry 1-2 yards safely; larger trucks or trailers needed for more.
Should I get screened or unscreened loam?
Screened loam has been sifted to remove rocks, sticks, and large debris. Cost ~$15-$25 more per yard but 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.