The Formula
Topsoil is sold by the cubic yard. Your project is measured in square feet and inches. The conversion formula bridges those units:
Length (ft) × Width (ft) × Depth (in) ÷ 324 = cubic yards
The 324 divisor comes from two conversions stacked together: divide inches by 12 to get feet (converting your depth), then divide cubic feet by 27 to get cubic yards (since 1 cubic yard = 27 cubic feet). Multiply those: 12 × 27 = 324. That's the whole math. You don't need to do it in two steps — just use 324 as the divisor directly.
Example: a 50 × 40 foot lawn area at 4 inches deep.
50 × 40 × 4 ÷ 324 = 24.7 cubic yards.
Reference Table for Common Projects
Topsoil Calculator — Common Project Sizes
| Project | Area | Depth | Cubic Yards |
|---|---|---|---|
| 10×20 raised bed | 200 sq ft | 12 in | 7.4 yd³ |
| Average lawn repair | 500 sq ft | 4 in | 6.2 yd³ |
| 50×50 yard top-dress | 2,500 sq ft | 2 in | 15.4 yd³ |
| 100×100 yard top-dress | 10,000 sq ft | 2 in | 61.7 yd³ |
| Large grading project | 5,000 sq ft | 6 in | 92.6 yd³ |
Always Add 10–15% Overage
Topsoil settles after it's placed and watered — typically 10 to 15 percent. A 4-inch layer will compact down to roughly 3.5 inches after the first rain and initial watering. If you're trying to hit a specific final depth, the delivered depth needs to account for that settlement.
The practical rule: multiply your calculated cubic yards by 1.12 to 1.15 and round up. It's far easier to use a small leftover pile than to wait for a second delivery because you came up short at the end of the job.
Depth Guidelines by Application
How deep you need to go depends on what you're growing and what the current soil condition is:
- Lawn establishment (new seed or sod): 4 to 6 inches minimum. Less than 4 inches and roots hit the subsoil layer too quickly, resulting in thin turf that stresses in dry periods.
- Garden and planting beds: 8 to 12 inches is ideal. Vegetable gardens and perennial beds benefit from deeper topsoil — it gives roots room to develop and retains moisture through summer heat.
- Top-dressing and overseeding: 1 to 2 inches. Spread thin, raked lightly into existing turf to improve surface soil quality without smothering the existing grass.
- Grading and filling low spots: Variable — as deep as needed to achieve the target grade, plus 4 to 6 inches of topsoil on the surface as a growing layer. If filling more than 4 to 6 inches total, use fill dirt for the bulk elevation change and finish with topsoil. See fill dirt vs. topsoil for details on the layering approach.
What J1S Delivers
J1S runs quad-axle dump trucks that carry 14 cubic yards per load. That's the standard delivery unit. A 14-yard load of screened topsoil weighs roughly 14 to 15 tons, depending on moisture content.
If your project calculates out to 10 cubic yards, you'll receive a 14-yard load — which is fine; the extra material rarely goes to waste on a grading or lawn project. If your project is genuinely small — under 5 or 6 yards — contact us before ordering to discuss smaller-load options or yard pickup availability.
Check site access before scheduling delivery. A quad-axle truck is a large piece of equipment. The truck needs a clear drive path with adequate overhead clearance (watch for low tree branches and utility lines), firm enough ground to avoid getting stuck, and a workable turnaround or backup path. If site access is tight, call us — we can advise on what's workable.
Topsoil Quality: Screened vs. Unscreened
Not all topsoil is the same material. J1S supplies screened topsoil as the standard product — run through a screening drum that removes rocks, debris, roots, and large clods. The result is a consistent, workable material that rakes smooth and establishes quickly.
Unscreened topsoil is cheaper but contains whatever came out of the ground: rocks, root balls, construction debris, undecomposed organic matter. It's fine for rough fills where you're going to cover it with screened material anyway. For lawn establishment or planting beds, screened topsoil is the right product. Trying to establish a lawn in unscreened topsoil full of clods and rocks is a losing battle.
Weight and Site Access
Topsoil weighs approximately 2,000 to 2,200 lbs per cubic yard — roughly 1 ton per yard. A standard 14-yard delivery is approximately 14 tons of material. Most residential driveways and access paths handle this without issue, but saturated ground or recent excavation can be a problem. If you're in doubt about ground conditions, schedule delivery during dry weather.
Missouri Context: Why You Often Need More Topsoil Than You Expect
Jefferson County's native soil profile typically includes 4 to 8 inches of workable topsoil over clay subsoil. On undisturbed land, that's adequate for established turf and native plantings. On developed lots, that topsoil layer is often partially or fully stripped during construction — grading, foundation work, and utility installation removes it and replaces it with compacted subsoil or fill.
The result is that many residential lots in Jefferson County have 0 to 2 inches of topsoil over clay by the time the builder is done. Lawns established directly on that surface will be thin, patchy, and drought-stressed every summer. A 4-inch topsoil application over the compacted subgrade is the fix — and the formula above gives you the yardage to order.
For filling low spots or regrading before topsoil, see our guide on how much fill dirt you need — the formula is the same, but fill dirt is the right material for the structural layer below the topsoil finish.