Topsoil & Fill Dirt Calculator

Work out how much topsoil, fill dirt, compost or garden mix to order — in cubic yards, cubic feet, tons and bags — for rectangles, circles, triangles, irregular patches or several areas at once. The second mode does the job most dirt calculators skip: how much fill it takes to give your house the 6 inches of fall the building code asks for, without burying the siding.

The short version: cubic yards = length (ft) × width (ft) × depth (in) ÷ 12 ÷ 27, plus about 25% for settling. A 30 × 40 ft lawn at 4 inches needs 14.8 yards finished — order 18.5 yards, which weighs 15–21 tons.

Material

Area 1

Length (ft)Width (ft)Depth (in)

Uneven ground? Enter several depth readings separated by commas — e.g. 2, 5, 8 — and the average is used. 200 sq ft × 4 in = 66.7 cu ft

Settling allowanceLoose soil shrinks as it settles or is compacted. 25% is the default — see why below the calculator.

Order

3.1 cubic yards of topsoil

83.3 cu ft · about 2.5–3.5 tons · covers 200 sq ft. That's 2.5 yd³ finished plus a 25% settling allowance.

1 cu ft bags

1.5 cu ft bags

2 cu ft bags

6 cu ft wheelbarrow loads

Show the math

Area 1: 200 sq ft × (4 in ÷ 12) = 66.67 cu ft
Total 66.67 cu ft ÷ 27 = 2.47 yd³ finished
× 1.25 settling allowance = 3.09 yd³ to order
× 0.8–1.15 tons per loose yd³ = 2.47–3.55 tons

Weight basis: Caterpillar Performance Handbook: topsoil 950 kg/m³ loose, 1,370 kg/m³ in place. Screened loads sit near the low end; unscreened, clumpy or wet loads near the high end.

Bags or bulk? Use your local prices

Prices vary too much by region and season to publish one. Put in what your store and yard charge.

Bag size$ per bagBulk $ per yd³Delivery $

Enter a bag price and a bulk price to see which is cheaper and where they cross. The arithmetic: bag price × (27 ÷ bag size) is what bagged soil costs per yard; the break-even is the delivery fee ÷ (that − the bulk price per yard).

What this doesn't tell you

Weights are ranges because moisture swings them by a quarter or more — your supplier's ticket is the real number. The regrade assumes today's ground is a straight slope over the first 10 ft; dips and humps change the volume, so take depth readings every few feet on a big job. Inside corners overlap and outside corners need a little extra. Local codes can differ from the model IRC.

How the calculator works

Every area is converted to square feet — length × width for a rectangle, π × (diameter ÷ 2)² for a circle, ½ × base × height for a triangle, or the square footage you enter for an irregular patch. That's multiplied by the depth in feet (inches ÷ 12) for cubic feet, and divided by 27 for cubic yards. When the ground is uneven, enter several depth readings for an area and the average is used: on a dip that runs from 2 to 6 inches deep, the average of readings taken every few feet is a much better number than a single guess.

The settling allowance is added next, because loose soil shrinks. Then cubic yards are converted to tons using the material's weight range, and to bag counts for 1, 1.5 and 2 cubic-foot bags, rounded up.

Weights by material

Suppliers sell by the yard or the ton, so the weight per yard decides how a quote compares. These are loose, as-delivered weights, and they are ranges because water content moves them a lot.

Material	Tons per yd³	lb per yd³	Source
Topsoil (screened or unscreened)	0.8–1.15	1,600–2,300	Caterpillar Performance Handbook: topsoil 950 kg/m³ loose, 1,370 kg/m³ in place. Screened loads sit near the low end; unscreened, clumpy or wet loads near the high end.
Fill dirt (subsoil, common earth)	1.2–1.35	2,400–2,700	Caterpillar Performance Handbook loose densities: dry sandy fill 1,420 kg/m³ to wet excavated earth 1,600 kg/m³. Saturated sand can reach 1,840 (about 1.55 tons).
Compost	0.4–0.6	800–1,200	Oregon State University Extension (EM 9217): about 1,000 lb per cubic yard for screened compost at 50% moisture; 800–1,200 typical.
Garden mix (50/50 topsoil and compost)	0.6–0.88	1,200–1,750	Derived: the average of the topsoil and compost ranges above, for a half-and-half blend by volume. Blends vary — use the supplier's ticket weight if they give one.

Screened or unscreened? Screening breaks up clods and pulls out roots and stones, which leaves the soil fluffier — screened loads sit toward the low end of the topsoil range, unscreened toward the high end. We haven't found a published, independent density for each, so the calculator uses one sourced range for both rather than invent a split. As a cross-check on the topsoil range, USDA NRCS lists ideal dry bulk densities for growing soils of 1.10–1.60 g/cm³ by texture, which is 0.93–1.35 tons per cubic yard in place before any water is counted.

Why 25% for settling

Most calculators add 10% or nothing. The sources that measure it say more. Virginia Cooperative Extension's lawn guidance specifies 8 to 10 inches of loose topsoil to end up with 6 to 8 inches after settling — the loose layer is 25 to 33% deeper than the finished one. For fill that will be compacted, the Caterpillar Performance Handbook gives common earth a load factor of 0.79–0.80: a loose yard packs into about 0.8 of a yard in place, so a compacted yard takes about 1.25 loose yards. And even properly compacted fill keeps settling — the USDA NRCS pond standard (Code 378) makes earthen embankments at least 5% taller than design height to allow for it.

So 25% is the default for topsoil spread for a new lawn and for compacted fill alike. For a thin topdressing raked into existing grass, or a raised bed you'll top up next spring anyway, 10–15% is enough. Compost settles more than either as it keeps breaking down.

Coverage per cubic yard

Finished cubic yards needed for common areas and depths, before the settling allowance.

Depth	1 yd³ covers	100 ft²	250 ft²	500 ft²	1,000 ft²	1,500 ft²	2,000 ft²
1 in	324 ft²	0.31	0.78	1.5	3.1	4.6	6.2
2 in	162 ft²	0.62	1.5	3.1	6.2	9.3	12.3
3 in	108 ft²	0.93	2.3	4.6	9.3	13.9	18.5
4 in	81 ft²	1.2	3.1	6.2	12.3	18.5	24.7
6 in	54 ft²	1.9	4.6	9.3	18.5	27.8	37.0
8 in	41 ft²	2.5	6.2	12.3	24.7	37.0	49.4
12 in	27 ft²	3.7	9.3	18.5	37.0	55.6	74.1

Bags or bulk

A cubic yard is 27 one-cubic-foot bags, 18 bags of 1½ cubic feet or 13½ two-cubic-foot bags. Bagged soil almost always costs more per yard than bulk; what keeps bags competitive on small jobs is the delivery fee bulk carries. That makes the break-even simple: break-even yards = delivery fee ÷ (bag price × 27 ÷ bag size − bulk price per yard). Below it, buy bags; above it, order bulk. Enter your local prices in the calculator to get your number — we don't print prices we can't source for your area. Check the bulk yard's minimum order, and remember that a pickup's limit is weight, not volume: two yards of damp topsoil is 1.6–2.3 tons, so compare it with the payload on your door-jamb sticker before you load.

Regrading: fill to slope the ground away from the house

The International Residential Code sets the target in section R401.3: “Lots shall be graded to drain surface water away from foundation walls. The grade shall fall not fewer than 6 inches (152 mm) within the first 10 feet (3048 mm).” Where a lot line, wall or slope makes that impossible, the exception requires “drains or swales” to carry water away instead, and paved surfaces within 10 feet must slope at least 2 percent away from the building.

Raising the ground at the wall is the usual fix, and the soil it takes is a wedge: full height at the wall, thinning to nothing 10 feet out. Its cross-section is a triangle, so wedge volume = ½ × raise at the wall (ft) × 10 ft × wall length (ft). The raise is 6 inches minus whatever fall you already have — so ground that slopes 1 inch toward the house needs 7 inches at the wall.

The catch is the other code limit. Soil can only go so high before it buries the bottom of the wall. Section R404.1.6 requires foundation walls to “extend above the finished grade adjacent to the foundation at all points not less than 4 inches (102 mm) where masonry veneer is used and not less than 6 inches (152 mm) elsewhere.” Section R317.1 requires wood protection for “wood siding, sheathing and wall framing on the exterior of a building having a clearance of less than 6 inches (152 mm) from the ground,” and R703.7.2.1 puts a stucco weep screed “a minimum of 4 inches (102 mm) above the earth.” When the room at the wall is less than the raise you need, the calculator raises the wall end as far as is allowed and shows the rest as soil to cut away further out — where the new grade crosses the old, and how much comes off.

Worked examples

A new lawn, 30 × 40 ft, 4 inches of topsoil

1,200 sq ft × (4 ÷ 12) = 400 cu ft ÷ 27 = 14.8 yd³. With 25% for settling, order 18.5 cubic yards — 14.8 to 21.3 tons, or 250 two-cubic-foot bags, which is why a lawn is a bulk job.

A round garden bed, 8 ft across, 8 inches of garden mix

π × 4² = 50.3 sq ft × (8 ÷ 12) = 33.5 cu ft. With the allowance that's 1.6 yd³, about 0.9–1.4 tons, or 28 bags of 1.5 cu ft. Garden mix weighs 0.6–0.88 tons a yard, much less than topsoil.

Filling a low spot, about 150 sq ft, readings of 2, 4, 6 and 3 inches

The average depth is 3.75 in, so 150 × (3.75 ÷ 12) = 46.9 cu ft. Order 2.2 yd³ of fill (2.6–2.9 tons) — and before you fill it, read why water stands there; a low spot over clay often needs a path out, not just more soil.

An L-shaped yard as two areas

A 25 × 12 ft strip plus a triangular corner with an 18 ft base and 10 ft height, both at 3 inches: 390 sq ft and 97.5 cu ft in all. Order 4.5 yd³ of topsoil.

Regrading a 40 ft wall that slopes 1 inch toward the house, 14 inches of foundation showing

The raise needed is 6 − (−1) = 7 inches; there's room for 8, so the whole raise goes at the wall. The wedge is ½ × (7 ÷ 12) × 10 = 2.92 sq ft per foot × 40 ft = 116.7 cu ft. With a 4-inch topsoil cap that splits into 95.2 cu ft of topsoil and 21.4 cu ft of fill; with the 25% allowance, order about 4.4 yd³ of topsoil and 1.0 yd³ of fill. 7 inches of foundation still shows afterwards.

The same wall on flat ground with only 10 inches showing

Now the soil at the wall can rise just 10 − 6 = 4 inches, two short of the 6 needed. Raise it 4 inches and lower the ground 10 feet out by 2: the new grade crosses the old about 6.7 ft from the wall. That's 44 cu ft of fill near the house and 11 cu ft to cut further out — often the cut soil can go straight into the wedge. Where the far end can't come down, the code's answer is a swale.

Regrading done right

Measure the fall first. A string line and line level from the wall out 10 feet gives the existing fall; the yard slope calculator converts it and explains the method.
Strip the sod, then place fill in lifts of a few inches, tamping each. Loose fill against a wall settles back into a trough that holds water right where you don't want it.
Use soil that sheds water under the cap — clay-rich fill, not sand, gravel or mulch, which let water soak straight down beside the foundation.
Cap with 4–6 inches of topsoil and seed or sod it the same week so rain doesn't wash the new slope away.
Sort out the roof water. Downspouts that empty at the wall will beat any grade; see water pooling near the foundation for the order to do things in.

The wider decisions — when to regrade, when a drain is the better fix, and what grading costs — are on yard grading and resloping.

Frequently asked questions

How much topsoil do I need?

Multiply length × width in feet for the area, multiply by the depth in inches ÷ 12 for cubic feet, and divide by 27 for cubic yards. Then add a settling allowance — we use 25%. A 30 × 40 ft lawn at 4 inches is 400 cu ft, 14.8 cubic yards finished, so order about 18.5 yards.

How much area does a cubic yard of topsoil cover?

A cubic yard is 27 cubic feet, so it covers 324 sq ft at 1 inch deep, 162 sq ft at 2 inches, 108 at 3 inches, 81 at 4 inches and 54 at 6 inches — before settling. Divide 324 by your depth in inches for any other depth.

How much topsoil do I need for 1,000 square feet?

6.2 cubic yards at 2 inches, 12.3 at 4 inches and 18.5 at 6 inches, finished. Add the settling allowance on top: at 25%, 4 inches over 1,000 sq ft means ordering about 15.4 yards.

Is 1 yard of dirt equal to 1 ton?

Not quite, and it depends on the dirt. Loose topsoil runs about 0.8–1.15 tons per cubic yard and fill dirt 1.2–1.35, from the Caterpillar Performance Handbook's loose and in-place densities. Compost is far lighter at 0.4–0.6 tons (Oregon State University Extension). Water is most of the swing: a wet load can weigh a quarter more than a dry one.

How much does a cubic yard of topsoil weigh?

About 1,600–2,300 lb (0.8–1.15 tons). The low end is loose, screened topsoil (950 kg/m³ in the Caterpillar handbook); the high end is the same soil packed back to its in-place density (1,370 kg/m³), which is roughly what a damp, unscreened load weighs. Fill dirt is heavier: 2,400–2,700 lb.

How much will 1 ton of topsoil cover?

One ton is about 0.87–1.25 cubic yards of topsoil, so roughly 141–203 sq ft at 2 inches deep. If your supplier sells by the ton, ask for their weight per yard — it's on the scale ticket.

How many bags of topsoil make a cubic yard?

27 one-cubic-foot bags, 18 bags of 1.5 cu ft, or 13½ two-cubic-foot bags (so 14). Go by the cubic feet printed on the bag, not its weight — weight changes with moisture, the volume on the label doesn't. A 0.75 cu ft bag spread 2 inches deep covers 4.5 sq ft.

Is it cheaper to buy topsoil in bags or bulk?

Bags win on small jobs, bulk on big ones, and the crossover is set by the delivery fee. Bagged soil costs (bag price × 27 ÷ bag size) per cubic yard; the break-even is the delivery fee ÷ (that figure − the bulk price per yard). Put your local prices into the calculator and it works it out — we don't publish prices because they vary too much by region to be honest.

How many wheelbarrows are in a yard of dirt?

About 4½ loads in a standard 6 cu ft contractor wheelbarrow filled level, so plan on 5 trips per yard. Heaped loads cut that slightly; a smaller 4 cu ft barrow takes about 7.

Is 3 inches of topsoil enough to grow grass?

It's thinner than extension services recommend for a new lawn. New Mexico State University Extension calls for a total topsoil depth of 4–6 inches after firming; Virginia Cooperative Extension asks for 6–8 inches after settling. Three inches spread over loosened ground can carry grass, but it dries out faster and roots stay shallow.

How much should I add for settling and compaction?

We default to 25%. Virginia Cooperative Extension specifies 8 to 10 inches of loose topsoil to finish at 6 to 8 inches after settling — 25 to 33% more than the finished depth. For compacted fill, the Caterpillar handbook's load factors of 0.79–0.80 for earth mean a loose yard packs to about 0.8 of a yard, so you need about 1.25 loose yards per compacted yard. Drop it toward 10% for a thin topdressing raked into existing turf.

How much fill dirt do I need to grade away from my house?

The code target is 6 inches of fall in the first 10 feet (IRC R401.3). If the ground is flat and you raise it at the wall, the added soil is a wedge: ½ × 0.5 ft × 10 ft = 2.5 cubic feet per foot of wall. Along a 40 ft wall whose ground falls 1 inch toward the house you'd need a 7-inch raise — 117 cu ft, or about 5.4 yards ordered with the allowance. The regrading mode works it out for each wall.

How high can I build soil against my foundation?

Leave at least 6 inches of foundation showing above the finished grade — 4 inches where the wall is brick or stone veneer (IRC R404.1.6). Wood siding, sheathing and framing closer than 6 inches to the ground must be pressure-treated or naturally durable (R317.1), and a stucco weep screed must stay at least 4 inches above the earth (R703.7.2.1). If there isn't room to raise the soil at the wall, lower the yard further out or cut a swale instead.

Should I use fill dirt or topsoil to regrade?

Both, in layers. Fill dirt — subsoil with little organic matter — compacts firmly and doesn't rot down, so it builds the bulk of the slope. Topsoil goes on top, 4 to 6 inches, so grass can grow. A slope built entirely of topsoil settles as the organic matter breaks down, and one finished in bare fill won't hold turf.

Sources

International Code Council, International Residential Code (2021): R401.3 Drainage; R404.1.6 Height above finished grade; R317.1 Location required (item 5); R703.7.2.1 Weep screeds. Your local adoption may differ.
Caterpillar Performance Handbook, material densities and load factors (topsoil, earth, clay, sand), as reproduced in Methvin's density and load factor table.
Oregon State University Extension, EM 9217, Interpreting Compost Analyses — compost bulk density.
USDA NRCS, Soil Bulk Density — Soil Health Guide — ideal and root-limiting bulk densities by texture.
Virginia Cooperative Extension, Master Gardener Handbook, Chapter 11: Lawns — loose vs settled topsoil depth.
New Mexico State University Extension, Guide H-509, Turfgrass Establishment — 4–6 inches of topsoil after firming.
USDA NRCS Conservation Practice Standard 378, Pond — settlement allowance for compacted earth fill.

Every constant the site's tools use is listed on how we calculate.

Yard slope calculator — measure the fall you have before you order dirt
Yard grading and resloping — when regrading is the right fix, and what it costs
Water pooling near the foundation — grade, downspouts and what to check first
How to drain a flat yard — when there's no fall to work with
Retaining wall vs regrading vs terracing — for slopes too steep to regrade
French drain gravel calculator — stone, pipe and the topsoil to cap a trench