Topsoil Calculator

How it's calculated

The calculator first finds the volume of the area in cubic feet: length (ft) × width (ft) × depth (in ÷ 12). That's converted to cubic yards by dividing by 27, since a cubic yard is 3 ft × 3 ft × 3 ft. A waste percentage is added on top — higher than for aggregate, since topsoil settles more once it's watered in — and the adjusted cubic yardage is multiplied by topsoil's density (tons per cubic yard) to get the weight in tons. Bag counts divide the adjusted cubic feet by each bag's yield; truckloads divide the adjusted cubic yards by the truck's capacity.

Worked example

A 10 ft × 10 ft garden bed at 6 inches deep: volume = 10 × 10 × (6 ÷ 12) = 50 cubic feet. In cubic yards, that's 50 ÷ 27 = 1.85 yd³. Adding a 15% waste factor: 1.85 × 1.15 = 2.13 yd³. At 1.10 tons per cubic yard, that's 2.13 × 1.10 = 2.34 tons — or 1.92–2.88 tons across the full 0.90–1.35 density range, since topsoil's weight swings more than gravel or sand depending on moisture. In 1.5 cu ft bags, the adjusted 57.5 cu ft (50 × 1.15) needs 39 bags — right at the edge of where bulk delivery starts making more sense.

How deep should it be?

Topsoil depth depends on what's being planted and how established it already is, more than on any structural requirement. A 3" layer is right for topdressing — leveling low spots in an existing lawn or prepping bare, graded ground before a full reseed. That's a heavier pass than routine overseeding maintenance, which typically only needs a thin 1/4"–1/2" layer worked into the existing grass; use the 3" preset when you're correcting the lawn's surface, not just refreshing it. A 6" layer is standard for a new garden bed, deep enough for most annuals and shallow-rooted perennials. A 12" (or deeper) raised bed gives vegetables and deeper-rooted plants room to establish without hitting a hard boundary. Whatever the target, order based on the settled depth you want — topsoil is sold and delivered loose, and it compacts noticeably once it's watered in and walked on, more than gravel or sand does, which is why the waste factor here defaults higher than on the aggregate calculators.

Common mistakes

• –Confusing topsoil, fill dirt, and garden soil blends. Fill dirt is unscreened subsoil for grading, not planting; garden soil blends add compost and amendments that plain topsoil doesn't have.
• –Measuring depth as the loose delivered pile instead of the settled depth — topsoil compacts significantly once watered in and walked on, more than aggregate does.
• –Underfilling a raised bed. A 12" bed filled with only 6" of topsoil leaves roots shallow and dries out faster than a properly filled bed.
• –Topdressing a lawn too thick in one pass for routine maintenance. More than about 1/2" over existing grass can smother it — save a heavier 3" pass for leveling or full reseeding.
• –Ordering bagged topsoil for a job that's really a bulk order. Past roughly a cubic yard, bagged topsoil runs well above the per-yard cost of a bulk delivery.

Where the density figure comes from

Sourced from three suppliers rather than the usual two, because topsoil varies more by region, screening, and moisture than a manufactured material like gravel does — one pair of sources risked missing the real spread. Ottr Landscape Supply (Greater Boston) and Woodland Earth (Wooster, Ohio) both put screened or typical moist topsoil at about 2,200 lb (1.10 tons) per cubic yard. Yard Works Landscape Supply's premium screened topsoil runs lighter, about 1,800 lb (0.90 tons), and anchors the low end of the published range. The spread comes from organic content, how finely the material is screened, compaction, and above all moisture — Ottr notes clay-heavy topsoil can approach 3,000 lb per yard when saturated. We use 1.1 tons/yd³ as the display figure, drawn from:

• Ottr Landscape Supply — How Much Does a Yard of Dirt Weigh?
• Woodland Earth — Screened Topsoil
• Yard Works Landscape Supply — Premium Screened Topsoil

Read more in our density methodology.

FAQ

How much topsoil do I need for a raised bed?

For a 4 ft × 8 ft raised bed filled 12" deep, that's 4 × 8 × 1 = 32 cubic feet, or about 1.19 cubic yards before waste. Use the calculator above with your waste factor to get the exact bag count or bulk order, since raised beds settle noticeably in the first few waterings.

What's the difference between topsoil, fill dirt, and garden soil?

Fill dirt is unscreened subsoil used for grading and filling low spots — it's not meant to support plant growth. Topsoil is the nutrient-rich upper soil layer, often screened to remove rocks and debris. Garden soil blends start with topsoil and add compost or amendments for planting beds. Use topsoil for lawns and general planting, garden soil blends for vegetable beds, and fill dirt only for grading.

Why does topsoil weight vary so much more than gravel or sand?

Topsoil's weight depends on organic content, how finely it's screened, compaction, and above all moisture — and it holds water far more than mineral aggregates do. Two of our three cited suppliers put screened topsoil at about 2,200 lb (1.10 tons) per cubic yard; a third, lighter premium screened product comes in around 1,800 lb (0.90 tons). Ottr Landscape Supply notes clay-heavy or saturated topsoil can run well above either figure.

Should I order based on the loose or settled depth?

Settled. Topsoil compacts noticeably once it's watered in, rained on, and walked on — more so than sand or gravel. Order based on the depth you want after it settles, and let the waste factor cover the difference, or you'll find your bed or lawn a noticeable inch or two short a few weeks later.

How much topsoil should I use to topdress a lawn?

A thin refresh pass for routine overseeding is usually just 1/4"–1/2", spread to work into the existing grass rather than bury it. A heavier 3" application makes sense when leveling significant low spots or prepping bare ground before a full reseed — that's the depth this calculator's topdressing preset assumes.

Is bagged or bulk topsoil cheaper?

Bulk wins past about a cubic yard. Bagged topsoil carries packaging and handling costs that add up fast once you're buying more than a few dozen bags — a raised bed or small planting area is usually the ceiling for where bags still make sense over a bulk delivery.

How many truckloads of topsoil will I need?

Divide your adjusted cubic yardage by the truck's capacity — most standard dump trucks carry about 10-14 cubic yards. The calculator above uses 12 cubic yards as a default and rounds up, since a partial truckload still requires a full trip.