Topsoil Calculator

The dirt arithmetic, spelled out

cu yd = area sq ft × (depth in ÷ 12) ÷ 27. The worked path: 200 sq ft × 0.25 ft = 50 cu ft = 1.852 cu yd. A 10% cushion for settling and uneven grade lifts it to 2.037 cu yd, ordered as 3 whole yards with 0.96 cu yd to spare. Both conversions are definitions — 12 inches to the foot, 27 cubic feet to the yard — so the only judgment in the whole chain is the cushion you control. Every figure on this page was produced by the same engine that runs the form, when the page was built.

The units underneath that chain — why a cubic yard holds exactly 27 cubic feet, how a footprint and a depth become a volume, and what the inches-versus-feet slip does to the result — are the subject of the guide Cubic feet, cubic yards, and ordering concrete. It is written around concrete, but the volume arithmetic is identical for soil; read it first if the conversions are new to you. What differs for soil is what the rest of this page covers: an order rounded to whole yards rather than quarter yards, a footprint that can come from an area field as well as from length × width, a weight line that exists only when you supply the density, and a bag mode the tool deliberately does not have.

What the calculator computes, stage by stage

Every estimator on this site follows the five-stage pipeline documented on the methodology page. The topsoil tool runs all five, carrying the worked bed through each, and then adds one line that is not a stage of the pipeline at all.

1. Geometry. The footprint comes one of two ways: length times width, or the total-area field when it holds a number. Either way the engine ends up with square feet. The depth is divided by 12 to turn inches into feet, and the footprint times that decimal depth is the net volume in cubic feet — 200 × 0.25 = 50 for the worked bed. Dividing by 27 gives 1.852 cu yd. In metric mode the meters, centimeters, or square meters you type are converted to feet, inches, and square feet first, so the arithmetic downstream is identical in both systems.
2. Coverage. On most tools this stage divides by a published yield — how much one bag or box covers. Bulk soil has no package: the unit of purchase is the cubic yard itself, so the coverage divisor is the definition 27 cu ft per cu yd, and no manufacturer figure enters this page. Bagged soil is left to the bag label on purpose, as the FAQ explains.
3. Waste. The cushion is applied to the cubic-feet volume as net × (1 + cushion ÷ 100) before anything is rounded. The default of 5% is a trade convention for bulk aggregate recorded in the site's materials data, not a measured figure, and the form lets you replace it; the worked bed above used 10%. The result, converted to cubic yards, is the adjusted volume: what the job is expected to consume.
4. Package rounding. The "package" is one cubic yard. The engine computes ceil(adjusted cu yd ÷ 1) — 2.037 becomes 3 — and reports the spare, 0.96 cu yd here, as the order minus the adjusted volume. This is the only rounding in the chain and it always rounds up. When the division lands on a whole number within floating-point noise, the engine treats it as an exact fit rather than adding a phantom yard.
5. User-priced cost. If you type a price per cubic yard, the cost is that price times the ordered quantity — the rounded figure, not the adjusted one, because the rounded figure is what you buy. The site never supplies or averages a price; leave the field blank and the line does not appear.

The tons line sits outside the pipeline. When a density is entered, the engine multiplies the adjusted cubic yards — not the whole-yard order — by it and reports the product as tons. Nothing is rounded and nothing is looked up: the density is yours, and the engine only checks that it is positive and no more than 10 tons per cubic yard, a sanity ceiling rather than a statement about soil.

Why each input matters

Length and width set the footprint, and the volume scales with each of them directly: doubling either doubles the order before rounding. Both go in as decimal feet, so a tape reading in feet and inches is converted first — the feet & inches calculator does that for any reading. The engine does not care what shape produced the product; it only multiplies the two fields.

The total-area field replaces length and width when it holds a number. It is the route for anything that is not one rectangle — an L-shaped bed, a border around a patio, several beds ordered together: total the areas with the square footage calculator and paste the sum here. The engine itself refuses to be given both a footprint and an area, so the form resolves the conflict in the area field's favour and ignores the length and width fields while it is filled. Clear it when you go back to measuring by sides.

Depth is the input to watch. It is small, it is entered in a different unit from the sides, and it comes from your project rather than from this calculator: the tool sizes the load for whatever depth you give it and makes no judgment about what depth a lawn, a sod base, or a planter needs — that is the agronomy and grading question the FAQ sends elsewhere. Arithmetically it is a straight multiplier, so every extra inch adds exactly what the first inch did, and the unit slip described below is proportionally costly.

Extra cushion multiplies the volume, so it moves the adjusted figure proportionally and the order in whole-yard steps. Small changes often change nothing, because the round-up absorbs them; then a further change tips the order by a yard. The convention exists because a spread depth is never perfectly uniform and the ground beneath it is never perfectly flat. Set it to zero for the pure geometry — the raised-bed example below shows what zero does and does not remove.

Supplier density is optional and comes only from you. It touches nothing but the tons line, so adding or changing it never disturbs the volume or the order. It is entered in US tons per cubic yard: a figure quoted in pounds per cubic yard must be divided by 2,000 — pounds per US short ton, a definition held in the site's converter — before it goes in.

Price per cubic yard likewise touches only the last line and multiplies the rounded order, so the cost already includes the spare.

The units toggle changes what the fields expect and how the result is presented, not what is computed. In metric mode, meters are divided by 0.3048, centimeters by 2.54, and square meters by 0.09290304 — all exact definitions — before the engine sees them, and the result panel leads with cubic meters while still reporting the whole US yards to order.

The figures this page relies on

• Default cushion, 5% — a common trade convention for bulk aggregate recorded in the site's materials data, where it is labelled a convention because no primary source publishes a universal figure; depth variation is the main overrun it covers. Adjustable in the form, including down to zero.
• Ordering unit, one cubic yard — a convention about how US suppliers typically sell bulk soil, held in the topsoil engine as the package size for the round-up. A supplier who sells part yards changes only the last step; the unrounded figure is on the result for that case.
• Inches per foot, 12, and cubic feet per cubic yard, 27 — definitions, exact.
• Meters per foot, 0.3048, centimeters per inch, 2.54, and square meters per square foot, 0.09290304 — exact definitions, used only to convert metric entries into the engine's feet, inches, and square feet; cubic meters per cubic foot, 0.028316846592, presents the volumes back in m³.
• Density ceiling, 10 tons per cubic yard — a validation limit shared with the gravel engine, not a property of any soil. It exists to catch a figure entered in the wrong unit.
• Pounds per US short ton, 2,000 — a definition from the site's unit converter, mentioned here only so a pounds-per-yard quote can be turned into the tons-per-yard figure the field expects.
• Density and bag yield — none. This page holds no soil weight and no bag-coverage figure. Both vary by product and by the week's weather, so both belong to your supplier's quote and your bag's label.

Worked examples

Every figure in this table was produced at build time by the same engine that runs the form above. The inputs are chosen to show different behaviours of the pipeline: the lawn row came in through the area field, the raised bed appears with and without a cushion, and the metric row was entered as meters and centimeters and converted exactly before the engine ran, which is what the metric toggle does.

The lawn, through the area field. A 1,200 sq ft lawn top-dressed 1 in deep is not a rectangle anyone measured as two sides, so the square footage goes straight into the area field. At 1 ÷ 12 = 0.0833 ft the net volume is 100 cu ft, 3.704 cu yd; the default 5% takes it to 3.889 cu yd; and the order is 4 cu yd with 0.111 cu yd spare. A thin layer over a large area and a deep layer over a small one are the same arithmetic — only the product of area and depth reaches the engine.

The raised bed, with and without a cushion. An 8 × 4 ft planter filled 12 in deep — exactly one foot — is 32 sq ft and 32 cu ft, 1.185 cu yd net. With the cushion set to 0 the adjusted volume equals the net volume, yet the order is still 2 cu yd with 0.815 cu yd spare, because the whole-yard round-up does not go away when the allowance does. Restore the default 5% and the adjusted volume rises to 1.244 cu yd, the order stays at 2, and the spare shrinks to 0.756. On an order this small the rounding is a larger share than the cushion — which is the scale at which a supplier's part-yard scoop, or the bag label, is worth comparing against the unrounded figure.

The new lawn base. 40 × 25 ft at 4 in is 1,000 sq ft; at 4 ÷ 12 = 0.3333 ft deep that is 333.33 cu ft, 12.346 cu yd net. The cushion lifts it to 12.963 cu yd and the order is 13 cu yd with only 0.037 cu yd of rounding. A large adjusted volume rarely sits far below a yard boundary, so on a big load the spare is a small fraction and the cushion, not the rounding, is what governs the order. If the soil is going under new turf, the sod calculator counts the rolls that land on top.

The lawn levelling job. 40 × 24 ft at 2 in is 960 sq ft and 160 cu ft — 5.926 cu yd net, just under a whole number of yards. That is the situation in which the cushion decides the order: at 5% the adjusted volume is 6.222 cu yd and the order 7 cu yd with 0.778 spare. The same job reappears under common misreadings below, because it is also the example on which a cushion typed in the wrong form changes the order.

The load with a density. 30 × 15 ft at 6 in — half a foot — is 450 sq ft and 225 cu ft, 8.333 cu yd net, 8.75 cu yd adjusted, ordered as 9. Suppose the density field holds a stand-in of exactly 1 ton per cubic yard — a number chosen because it says nothing about real soil, not a figure to reuse. The tons line then reads 8.75, identical to the adjusted volume, which is the point: tons are the adjusted cubic yards times the density. Had the engine multiplied the whole-yard order instead, the line would read 9. Double the stand-in to 2 and the line doubles to 17.5 while every volume on the result is unchanged. The only density that belongs in the field is the one your supplier quotes for the material on the truck.

The priced order. 24 × 18 ft at 2 in is 72 cu ft net, 2.8 cu yd after the 5% cushion, and an order of 3 cu yd. With $100.00 per cubic yard typed into the price field, the cost line reads $300.00 — the ordered quantity times the price, nothing else. That price is a placeholder chosen only to show the arithmetic; the site holds no soil prices, and the cost is computed on the rounded order because the rounded order is what you buy.

The metric bed. In metric mode, 6 × 3 m at 8 cm — the form's own placeholders — reaches the engine as 19.69 × 9.84 ft at 3.15 in. The footprint is 18 m² (193.75 sq ft) and the net volume 1.44 m³ — 50.85 cu ft, 1.883 cu yd. With 5% the adjusted volume is 1.51 m³, and the whole-yard convention rounds it to 2 cu yd, shown as 1.53 m³. The result panel leads in cubic meters, but the order underneath it is the same one the imperial path would produce from the converted dimensions.

How to read the result

The headline line is the purchase decision: Order N cu yd. Beneath it, Net shows the footprint the engine used and the bare geometry in cubic feet and cubic yards, so a typo in a dimension — or a stale area field — is visible before anything is padded; With N% extra shows the cushioned volume with the percentage that produced it; and Rounded to whole yards repeats the order with the spare in brackets, the soil the rounding added beyond the cushion. Read the net line to check your geometry, the adjusted line to check your allowance, and the order line to place the order. A tons line appears only when a density is entered and is labelled as computed at your supplier's figure; a cost line appears only when a price is. In metric mode the same lines lead with cubic meters, converted from the engine's figures with the exact factor above, and the whole-yard line is labelled as the US ordering figure. The copy button places a short plain-text summary of the result on the clipboard.

Common misreadings

Depth in feet. Depth goes in as inches; length and width as feet. Enter the worked bed's 3 in as 3 feet and the engine sees 36 in: the same 200 sq ft footprint becomes 600 cu ft, 22.222 cu yd net, and an order of 25 cu yd instead of 3 — 12 times the correct volume, because there are 12 inches to the foot. The engine cannot flag this, because a three-foot depth is a valid number; it is the geometry of a pile, not a bed. If the cubic-yard figure looks wildly high, check the depth field first. The mirror-image slip — a depth measured in feet typed into the inches box — under-buys by the same factor.

Metric figures in the imperial fields. The metric bed above is 6 × 3 m at 8 cm. Type those same numbers with the toggle still on Imperial and the engine sees a 6 × 3 ft bed 8 in deep: 12 cu ft and an order of 1 cu yd, against the correct 2. The error is not a simple factor, because two of the three fields shrank and the third grew; if the order looks implausibly small for the bed, check the toggle.

A stale area field. Because the area field wins whenever it holds a number, a square footage left over from the last job silently overrides a fresh length and width. The net line names the footprint the engine actually used; if it does not match the sides you just typed, clear the area field.

Cushion as a fraction. The cushion field takes a percentage. The levelling job at 5% orders 7 cu yd; typed as 0.05 it is read as 0.05%, the adjusted volume falls to 5.929 cu yd, and the order drops to 6 — 1 cu yd short of the intended allowance, with no warning, because a fraction of a percent is a valid input.

Density in the wrong unit. The field takes US tons per cubic yard. A quote given in pounds per cubic yard, or in pounds per cubic foot, is a much larger number, and any figure above 10 is refused with the ceiling message — a useful tripwire. Divide a pounds-per-yard quote by 2,000 before entering it; the construction unit converter handles the other weight and volume units.

Reading the spare as an error. The spare is the round-up rule doing its job: the gap between the whole yards you can buy and the cushioned volume you expect to use. It is information, not a suggestion to order less — and it is never a full yard, because a full yard of slack would mean the round-up had gone one yard too far.

Padding twice. Rounding a dimension up before entering it, or adding a margin to the order afterwards, repeats work the pipeline already does: the cushion is applied to the volume and the round-up to the cushioned volume, exactly once each. The raised bed above shows what the rounding alone adds; the cushion is meant to be the only other margin.

Volume is measured; weight is quoted

A yard of soil is a yard of soil — but what it weighs depends on the week's rain and the mix's compost fraction, which is why this page ships without a density constant. When your supplier says what their screened topsoil runs per yard, type it into the density field and the tons line appears using their number, not an invented one. The same honesty rule governs cost: the only price in the output is the one you typed.

Where the model stops

The engine computes the volume of a flat layer at a uniform depth over the footprint you gave it, cushions that volume by one flat percentage, and rounds up to whole yards. Everything outside that sentence is left out on purpose. It does not model settling or compaction after spreading, so it estimates the day the soil goes down, not the depth you will measure after the first season; the cushion is the single flat percentage you are given to fold that into. It does not model a footprint that is anything but flat, or the extra material that low spots, feathered edges, and slopes consume beyond the cushion you set. It holds no density, so it cannot tell you what a load weighs until you do, and it holds no bag yield, so a bag count is arithmetic on the cubic-feet line and your bag's label. It does not know your supplier's minimum delivery, how a bulk load is measured at the yard, or whether that yard sells part yards. And it has no view on how deep the soil should be, what should be under it, or how the ground should drain — those are grading and agronomy judgments, and as the note under the form says, anything involving fill under structures, load-bearing, or permits needs a qualified contractor or engineer. The methodology page lists the simplifications every estimator shares.

Same pipeline, different material

Dirt, rock, sand, and bark all follow area × depth → waste → whole-unit order. For crushed stone or pea gravel use the gravel calculator; for bedding and fill sand the sand calculator runs the identical pipeline; for bark beds the mulch calculator adds standard 2 cu ft bag counts; and if the fresh soil is going under new turf, the sod calculator counts the rolls that land on top. The square footage calculator settles an irregular footprint before you come here, and the construction unit converter moves any figure between cubic yards, cubic meters, tons, and tonnes. For the units behind the chain, see cubic feet, cubic yards, and ordering concrete; for the one judgment input, waste factors, explained; or browse all guides.

Frequently asked questions

Nothing you type leaves your device. See how estimates are constructed and tested on the methodology page.