Topsoil Calculator

How topsoil quantities actually work

The math is simple — area × depth, in matching units — but the unit you order in (the cubic yard) is unintuitive for most homeowners, and that's where over-ordering or under-ordering happens. Here's what the calculator is doing under the hood, plus the practical knowledge that turns a number into a confident order.

What a "cubic yard" actually means

A cubic yard is a cube that's 3 feet on each side: 3 ft × 3 ft × 3 ft = 27 cubic feet. Picture a household washing machine — that's roughly 0.3 cu yd. A standard pickup truck bed (8 ft × 5 ft × 1.5 ft of usable depth) holds about 2 cu yd if heaped, or 1.5 cu yd loaded level with the rails. A full single-axle dump truck delivers 3–5 yards in one drop.

This matters because bulk topsoil suppliers price per yard, not per square foot. So the leap from area to volume is the whole calculation — and depth is the multiplier that controls everything.

Coverage: how far one cubic yard goes

One cubic yard of topsoil covers different areas depending on how thick you spread it. Memorize this table — it's the entire intuition you need:

The bottom row is also the simplest mental check: 1 yd at 12 in deep = 27 sq ft = a 3×9 patch. If your number wildly disagrees with this scale, you've got a unit mistake somewhere.

The math, walked through

For a 20 ft × 10 ft bed at 4 in deep:

1. Area: 20 × 10 = 200 sq ft.
2. Convert depth to feet: 4 ÷ 12 = 0.333 ft.
3. Volume in cubic feet: 200 × 0.333 = 66.7 cu ft.
4. Convert to cubic yards: 66.7 ÷ 27 = 2.47 cu yd.
5. Round up for waste, settling, and edge-piling: 2.5–3 cu yd to order.

Metric is gentler — it's all in the same family. Area in m², depth in m, volume in m³. No conversion factor.

Bulk vs bagged: the real break-even

Bagged topsoil at the big-box store runs $3–$6 per 0.75 cu ft bag (the common Scotts/Sta-Green size). Bulk delivered topsoil runs $20–$50 per cu yd — you'd need 36 bags to equal one yard. The break-even is brutal:

The break-even is around 0.7–1 cu yd (roughly 25–35 bags). Below that, bagged is right because you avoid the delivery fee and won't waste leftover. Above that, bulk wins decisively, and the gap widens fast.

Why your delivered amount may differ from the calculator

Three forces work against the clean math, and they all push you to order ~10–20% extra:

• Settling. Loose, fluffy topsoil settles 10–15% within the first week and another 5% over the season. A 4 in fill becomes a 3.5 in fill. Order assuming the final settled depth is what you want.
• Compaction differences. Suppliers measure "loose yards" off the conveyor. By the time you spread and water it, that yard occupies less volume in place. Reputable suppliers account for this; budget bargain piles often don't.
• Screening grade. "Screened" topsoil has been run through a 1/2" or 3/4" mesh — uniform texture, fewer rocks, costs more. "Unscreened" or "fill dirt" is cheaper but contains stones, root chunks, and clumps; you'll throw away 5–10% of what you ordered.

Topsoil weight and your driveway

One cubic yard of topsoil weighs 1,500–2,500 lbs (680–1,135 kg) depending on moisture and clay content — wet, heavy clay topsoil is the upper end. A 5-yard delivery is 4–6 tons of weight on a single dump truck. Two practical implications:

• Asphalt driveways can pothole or crack under the rear axle of a loaded tri-axle truck, especially in summer heat. Ask the supplier to drop on the street or at the curb if you're worried.
• A pickup-bed delivery at 2 cu yd is already 3,000–5,000 lbs in the bed. That's beyond the payload rating of most half-ton (F-150 / Silverado 1500) trucks. Don't haul more than 1 yd in a half-ton bed.

What "topsoil" actually is

The word is unregulated in most US states, so quality varies wildly. What you should actually ask the supplier for:

• Screened topsoil — basic, decent for fill, lawn dressing, or under sod. $20–$40/yd.
• 50/50 mix — half topsoil, half compost. Best for new garden beds and vegetable plots. $35–$60/yd.
• Triple mix / "garden soil" — topsoil + peat + compost. Premium stuff. $50–$85/yd.
• Fill dirt — NOT topsoil. Subsoil for filling holes and raising grade. $5–$15/yd. Don't plant in this.

Always ask: "Is this screened? What's the mix?" — the answer tells you whether the price is fair.

Measuring irregular areas

For non-rectangular beds, break the shape into rectangles, sum the areas, then plug into the calculator:

• L-shaped bed: two rectangles. Add them.
• Curved / kidney-shaped bed: sketch the bounding rectangle, then estimate that you're filling 70–80% of it. Multiply.
• Round bed (radius r): area = π × r². A 6 ft radius bed = 113 sq ft.
• Sloped lawn: measure horizontal area (the projection), not the surface length up the slope. The plants live in the soil column under the surface, not along it.

Common mistakes that cost money

• Using inches for depth without converting. 4 in × 200 sq ft is not 800 cu ft — that's the most common math error. Always divide depth by 12 first when working in feet.
• Confusing cubic yards with square yards. A "yard of carpet" is one square yard (9 sq ft). A "yard of topsoil" is one cubic yard (27 cu ft). Different measurements; same word; massive difference.
• Forgetting the depth grows under sod. If you're prepping a lawn for sod, the sod itself is 1 in thick. Order topsoil for the depth below the sod's root layer, not the finished grade.
• Ordering exact quantity. Always round up by 10–15%. Returning extra dirt is a non-event; running out at 4pm Saturday is a project killer.

Truck sizes and what fits in your delivery

• Pickup truck bed (DIY pickup) — 0.5 to 1 cu yd / 0.4–0.8 m³. You drive to the supplier yard, pay $0 delivery, and shovel it out yourself. Best for < 1 yd jobs.
• ½-ton dump or trailer (small delivery) — 1 to 3 cu yd / 0.8–2.3 m³. Common minimum for residential delivery; the supplier typically charges $40–$80 delivery.
• Single-axle dump truck — 3 to 5 cu yd / 2.3–3.8 m³. The standard residential workhorse. Will fit on most residential streets and driveways.
• Tandem / tri-axle dump — 10 to 16 cu yd / 7.6–12 m³. For large fills, regrading, or whole-property landscaping. Confirm your driveway can take the weight; many suppliers will dump in the street if asked.

Frequently asked questions