Topsoil Calculator

Filling a 20 ft × 10 ft garden bed (200 square feet) with 4 inches of fresh topsoil takes about 2.47 cubic yards - roughly 2.96 tons of soil, or about 89 of the standard 40 lb bags. That single example shows why this matters: a bed that sounds small still swallows almost three cubic yards, and buying it in bags instead of bulk would mean hauling dozens of sacks. This topsoil calculator turns your measurements into the exact volume, weight, and bag count so you order the right amount the first time.

The formula behind the numbers

Topsoil is sold by volume, and the volume of any flat layer is simply its area multiplied by its depth. The only trick is keeping the units consistent - depth is measured in inches but volume is in feet, so you divide the depth by 12 to convert it to feet:

There are 27 cubic feet in a cubic yard (3 ft × 3 ft × 3 ft), which is why we divide by 27 - the same conversion behind our Cubic Yard Calculator. To estimate weight, multiply the cubic yards by the topsoil density - about 1.1 to 1.3 tons per cubic yard. For bags, divide the cubic feet by the bag's volume; a 40 lb bag holds roughly 0.75 cubic feet.

A worked example, step by step

Take the 200 sq ft bed at 4 inches deep:

1. Convert depth: 4 inches ÷ 12 = 0.333 feet.
2. Cubic feet: 200 sq ft × 0.333 ft = 66.67 cubic feet.
3. Cubic yards: 66.67 ÷ 27 = 2.47 cubic yards.
4. Tons: 2.47 × 1.2 = about 2.96 tons.
5. Bags (40 lb): 66.67 ÷ 0.75 = about 89 bags.
6. Add 10% waste: order about 2.72 cubic yards to be safe.

The calculator runs all of this instantly when you enter your length, width, and depth - or just the total square footage if you already know it.

How to measure your area

Accurate measurements are the difference between one delivery and two. To get them right:

1. Measure length and width in feet with a tape measure or measuring wheel. For an irregular space, break it into rectangles, calculate each, and add them up.
2. Decide your depth based on the job (see the depth guide below) and enter it in inches.
3. For round beds, measure the radius (half the diameter), then area = 3.1416 × radius × radius. Enter that as total square feet, or work it out first with the Square Footage Calculator.
4. Subtract obstacles like existing plants, rocks, or paving you won't be covering.

How deep should the topsoil be?

Depth drives the volume more than almost anything else, so match it to the project:

• New lawn from seed or sod: 4-6 inches of quality topsoil for healthy roots.
• Topdressing an existing lawn: 0.25-0.5 inch in a thin layer.
• Garden and raised beds: 8-12 inches so roots have room to grow.
• Leveling and patching low spots: 1-3 inches, blended into the surrounding grade.
• Around new plantings: enough to cover the root ball plus a few inches.

Who this calculator is for

Anyone moving dirt benefits from a real number before ordering. That includes:

• Homeowners starting a new lawn, garden bed, or raised planter.
• DIY landscapers leveling a yard, fixing drainage, or building up a grade.
• Contractors and crews estimating loads and delivery for a client job.
• Gardeners filling beds, planters, and borders with the right soil volume.
• Anyone comparing the cost of bags at the store against a bulk yard delivery.

Key terms explained

• Cubic yard: a 3 ft × 3 ft × 3 ft block of material, equal to 27 cubic feet. The standard bulk unit for topsoil.
• Cubic foot: a 1 ft cube. Bagged soil is usually labeled in cubic feet (a 40 lb bag is about 0.75 cu ft).
• Density: how much a volume of soil weighs. Topsoil runs about 1.1-1.3 tons per cubic yard depending on moisture and organic content.
• Waste factor: the extra you order (about 10%) to cover settling, uneven ground, and spillage so you don't run short.
• Screened topsoil: soil run through a mesh to remove rocks and debris, giving a finer, more uniform fill.

Three quick scenarios

• New lawn, 1,000 sq ft at 5 inches: 1,000 × (5/12) = 417 cu ft = 15.4 cubic yards, about 18.5 tons. This is firmly a bulk-delivery job, not a bagged one.
• Raised bed, 4 ft × 8 ft at 10 inches: 32 sq ft × (10/12) = 26.7 cu ft = 0.99 cubic yards, about 1.2 tons, or roughly 36 bags. Right on the line between bags and bulk.
• Leveling a low spot, 150 sq ft at 2 inches: 150 × (2/12) = 25 cu ft = 0.93 cubic yards, around 33 bags. A small, baggable job.

What changes the result the most

Adjust the inputs and you'll see a few factors dominate:

• Depth: doubling the depth doubles the volume - going from 3 to 6 inches needs twice the soil.
• Area: the other direct multiplier; double the square footage, double the order.
• Soil moisture and type: wet or clay-heavy soil weighs noticeably more per yard, which matters for delivery limits and trailer loads.
• Bag size: switching between 20, 40, and 50 lb bags changes the count, though the total volume stays the same.

Practical tips

• Always order about 10% extra. A second small delivery usually costs more than the soil you saved by ordering tight.
• Buy bulk above about 1 cubic yard. Bags are convenient but pricey by volume; one yard is roughly 36 forty-pound bags.
• Check delivery weight limits. Many small dump deliveries cap around 1-2 tons; large jobs may need multiple loads.
• Stage the pile near the work area so you're not wheelbarrowing soil across the whole yard.
• Account for compaction on lawns - lightly settle and water, then check if you need a thin topup.

Limitations and assumptions

This is a planning estimate, not a guaranteed delivery quantity. Keep in mind:

• Weight uses a typical density of 1.1-1.3 tons per cubic yard; your supplier's screened, dry, or wet soil may differ.
• The bag count assumes a 40 lb bag holds 0.75 cubic feet; brands vary, so check the label's listed volume.
• It assumes even depth across a flat area - sloped or terraced ground needs a section-by-section estimate.
• It does not include delivery fees, taxes, or compaction beyond the 10% waste allowance.

Topsoil vs. other soil materials

"Soil" at a landscape yard is not one product. Knowing the difference keeps you from paying topsoil prices for fill, or trying to grow a lawn in something that won't support roots. The volume math is the same for all of them; only the price, weight, and purpose change:

• Topsoil: the nutrient-rich upper layer, general-purpose for lawns, grading, and bed fill. The default this calculator is tuned to (about 1.1-1.3 tons per cubic yard).
• Screened topsoil: topsoil run through a mesh to pull out rocks, roots, and clumps. Finer and more even, ideal for seeding a lawn or topdressing; usually a little pricier than unscreened.
• Garden soil / planting mix: topsoil blended with compost and nutrients for vegetable and flower beds. Lighter and richer, but more expensive per yard.
• Compost: decomposed organic matter used to amend or topdress. Lighter still (roughly 0.8-1.0 ton per yard), so the tonnage from this tool will overstate its weight.
• Fill dirt: subsoil with little organic matter, the cheapest option, used to build up grade where nothing needs to grow. Heavier and often denser than topsoil.
• Sand: used under pavers, in drainage, or to lighten heavy clay soil. Much heavier per yard (about 1.3-1.5 tons) - estimate it with the Sand Calculator.

Estimating the cost of your topsoil

Once the calculator gives you a cubic-yard total, turning it into a budget is straightforward. Bulk topsoil typically runs $15-$50 per cubic yard at the yard, with screened or premium blends at the higher end and plain fill-grade soil at the lower end. Two costs surprise people, so plan for them:

• Delivery: most suppliers charge a flat delivery fee (often $50-$150) based on distance, and may have a load minimum. A single larger order almost always beats two small ones once delivery is counted.
• Bagged premium: at roughly 36 bags per yard and a few dollars a bag, bagged soil can cost three to five times the bulk price per cubic yard. Reserve bags for jobs under about a yard.

To price a job, take the cubic yards from this tool, multiply by your local yard price, then add the delivery fee. For example, the 2.47-yard garden bed above at $35/yard is about $86 in soil plus delivery - clearly a bulk job, not 89 bags off a store shelf.

How to spread topsoil evenly

Ordering the right amount is half the battle; spreading it to a consistent depth is the other half, and it directly affects whether your estimate holds up. A few field-tested steps:

1. Prep the base: remove weeds and large debris, and loosen compacted ground so the new soil bonds instead of sitting in a slab on top.
2. Dump in stages: drop smaller piles around the area rather than one mountain, so you push soil short distances instead of hauling it across the whole space.
3. Rake to grade: use a landscape rake to pull the soil to your target depth, checking with a ruler or a marked stake in a few spots.
4. Use depth stakes for big areas: drive stakes marked at the finish depth so you can rake to a consistent level across a large lawn.
5. Settle and check: lightly water or roll a lawn area, let it settle, then add a thin topup where it sinks - this is exactly what the 10% waste allowance covers.

When to add topsoil

Timing affects both the result and how much waste you should plan for. Soil moisture is the biggest variable: wet soil weighs more and is harder to spread evenly, while bone-dry soil is dusty and blows around. Spring and early fall are the classic windows for new lawns because seed germinates well and the soil is workable. Avoid spreading right before heavy rain, which can wash thin layers away, or during a hard freeze, when the ground won't accept new soil. If you're topdressing an existing lawn, do it during the growing season so the grass can grow up through the thin layer rather than being smothered.

Working with your supplier and delivery

A short conversation with the yard prevents most ordering mistakes. Bring the cubic-yard number and tonnage from this calculator, and confirm a few things before you pay:

• What density do they quote? Suppliers vary; ask whether their tonnage assumes dry or moist soil so your weight estimate matches their loads.
• Truck access and drop spot: make sure the truck can reach where you want the pile, and that the pile won't block a driveway for days.
• Load limits: small dump deliveries often cap around 1-2 tons; a multi-yard order may need several trips, which changes the delivery cost.
• Screened vs. unscreened: for seeding a lawn, pay for screened soil so you're not raking rocks out by hand.

Related materials and tools

The same volume math powers our other landscape-material calculators. If you're working on a bigger project, a sister tool may fit better:

• For pouring slabs and footings, use the Concrete Calculator.
• For driveways and drainage stone, use the Gravel Calculator.
• For garden beds and tree rings, use the Mulch Calculator.
• For bedding sand and clay amendment, use the Sand Calculator.
• To convert any dimensions into bulk volume, use the Cubic Yard Calculator.
• To find an area before estimating material, use the Square Footage Calculator.

Sources

• USDA Natural Resources Conservation Service - soil texture, organic matter, and the role of the topsoil horizon.
• U.S. EPA - healthy soil, compost, and stormwater absorption.
• Volume conversions follow standard U.S. customary units (27 cubic feet = 1 cubic yard).