Topsoil Calculator
Work out how much topsoil, garden soil or compost you need for a new lawn, a top-dressing, a low spot or a raised bed. Enter each area with its own depth and get cubic yards, tons and bag counts with a settling allowance built in.
Material and depth
About topsoil
Penn State: a minimum of 4-6 in of settled topsoil to establish a lawn. Use less to top-dress or fill low spots.
From soil bulk density: SDSU Extension puts ideal density under 1.4 g/cm³ for loams and under 1.1 for clays, with 1.33 g/cm³ at 50% pore space; Cornell converts at 62.4 lb/ft³ per g/cm³, so 1.1-1.4 g/cm³ is 69-87 lb/ft³ and the midpoint, 78 lb/ft³ (about 1.05 tons per cubic yard), is stored. Wet or stony loads run heavier; bagged topsoil is a lighter peat blend (Timberline lists 38.5 lb per cu ft).
Areas
Measure each area and pick its shape. Leave an area’s depth blank to use the depth above.
Prices (optional)
Enter what your supplier or store charges to see the cost both ways.
Topsoil estimate
What to buy
6.19 yd³ of topsoil
Order 6.5 cubic yards in bulk, or buy 223 bags of 0.75 cu ft.
Includes 10% extra. Bulk suppliers usually sell in half-yard steps, so the order is rounded up.
Topsoil (screened) · Depth 6 in unless set per area · 10% extra
- Area
- 272 sq ft25.27 m²
- Cubic yards
- 6.19order 6.5 yd³
- Cubic feet
- 167.2
- Cubic metres
- 4.734,735 litres
- Weight
- 6.52 tons5.92 t, 13,042 lb
- Edging
- 88 ftperimeter of every area
| Bag size | Bags |
|---|---|
| 0.75 cu ft bag | 223 |
| 1 cu ft bag | 168 |
| 40 lb bag (0.75 cu ft per the listing) | 223 |
Your areas, to scale
| Area | Size | Depth | Volume |
|---|---|---|---|
| Lawn patch20 ft × 12 ft | 240 sq ft | 6 in | 120 cu ft |
| Raised bed8 ft × 4 ft | 32 sq ft | 12 in | 32 cu ft |
| Total | 272 sq ft | 152 cu ft | |
| With 10% extra | 167.2 cu ft | ||
How to use it
- Measure each area. Length and width for a lawn or a bed; inside dimensions for a raised bed, since the soil goes inside the boards. For a low spot in a lawn, measure its length and width and estimate its depth at the deepest point, then enter about half that depth, because a dip is deepest in the middle.
- Give each area its own depth. A lawn needs a few inches; a raised bed needs a foot or more; a top-dressing needs half an inch. One estimate can hold all three, and the result shows the breakdown.
- Pick the material. Screened topsoil for lawns and the top layer of beds, compost or a bagged garden-soil blend for planting. Fill dirt for raising a grade is not listed; estimate it by volume as topsoil and expect it to weigh more. The weight shown uses the density of the material you pick, where it is known.
- Allow for settling. Ten percent is a reasonable default for topsoil; raise it to 15 or 20 percent for a compost-heavy blend, which shrinks as it breaks down.
- Read the result. Cubic yards for a bulk delivery, tons where the density is known, bag counts for each bag size, and a per-area breakdown. Add prices to compare bulk with bags.
Raising a lawn versus filling beds
The two jobs use the same arithmetic and very different depths, and the depth decides everything. A new lawn needs 4 to 6 in of decent soil for roots; if the site already has a few inches of usable soil, you are only adding the difference. Top-dressing an existing lawn, to level it or feed it, is a layer of a quarter to half an inch: any deeper and the grass is smothered. A raised bed is filled to within an inch or two of the top board, so a 12 in bed takes 10 to 11 in of soil, and a tall bed is often filled with coarser, cheaper material in the bottom half.
That range is why the same 1,200 sq ft lawn needs 2.04 cubic yards for a half-inch top-dressing and 16.3 cubic yards for 4 in of new soil (both with 10 percent extra). Measure depth as carefully as you measure area.
Screened topsoil, fill dirt and blends
- Screened topsoil has been passed through a screen to remove rocks, roots and clods. It spreads and rakes evenly, which matters for lawns and for the top few inches of any bed. It costs more per yard than unscreened soil and is worth it everywhere you will see or plant into the surface.
- Unscreened topsoil is the same soil with the stones and lumps left in. Fine for the bottom of a deep bed or for raising a grade under a lawn, if you screen or rake the top layer yourself.
- Fill dirt is subsoil: dense, low in organic matter, cheap, and the right choice for changing a grade or filling a hole where nothing has to grow. It also settles less than topsoil, which is a point in its favour under a patio or a shed base.
- Garden soil and raised-bed mixes are bagged blends of topsoil, compost and often bark or peat. Lighter, richer and more expensive per cubic foot than plain soil, and they shrink more as the compost breaks down. Where a project needs both, enter the blend as a second material in the project planner.
Weight matters for soil because it decides between a pickup and a delivery. These are the densities the calculator uses, each from the sources listed below:
| Material | lb per cu ft | lb per cu yd | Tons per cu yd | Note |
|---|---|---|---|---|
| Compost | 40 | 1,080 | 0.54 | Oregon State (EM 9217): screened compost at 50% moisture is about 1,000 lb per cubic yard, very wet compost over 1,500; WSU uses 1,150 lb per cubic yard at 50% moisture. The midpoint of the two rules of thumb, 40 lb/ft³ (1,080 lb/yd³), is stored. |
| Topsoil (screened) | 78 | 2,106 | 1.05 | From soil bulk density: SDSU Extension puts ideal density under 1.4 g/cm³ for loams and under 1.1 for clays, with 1.33 g/cm³ at 50% pore space; Cornell converts at 62.4 lb/ft³ per g/cm³, so 1.1-1.4 g/cm³ is 69-87 lb/ft³ and the midpoint, 78 lb/ft³ (about 1.05 tons per cubic yard), is stored. Wet or stony loads run heavier; bagged topsoil is a lighter peat blend (Timberline lists 38.5 lb per cu ft). |
No weight is shown for garden soil mix: Scotts does not publish bag weights for Miracle-Gro Garden Soil (it varies with moisture), and bagged mixes are mostly composted forest products, far lighter than mineral topsoil, so weights are not shown.
Density figures for the soils in the calculator come from:
- Oregon State University Extension EM 9217, Interpreting Compost Analyses (read 2026-10-05)
- WSU Extension, Recommended Compost Best Management Practices for Farmers (2016) (read 2026-10-05)
- Oregon State University Extension EM 9308, How to Use Compost in Gardens and Landscapes (read 2026-10-05)
- University of Illinois Extension, Proper Mulching Techniques (2-4 in; composted 2-3 in, coarse 3-4 in) (read 2026-10-05)
- Lowe's listing: Black Kow 1-cu ft Organic Compost and Manure (read 2026-10-05)
- Lowe's category: Compost and manure, 40-lb bags (read 2026-10-05)
- SDSU Extension, Bulk Density: An Indicator of Soil Health (read 2026-10-05)
- Cornell Soil Health Lab, Fact Sheet 22-17: Bulk Density (1 g/cm³ = 62.4 lb/ft³) (read 2026-10-05)
- Penn State Extension, Lawn Establishment (read 2026-10-05)
- Scotts Miracle-Gro, Scotts Premium Topsoil product page (0.75 cu ft bag covers 4 sq ft at 2 in) (read 2026-10-05)
- Home Depot listing: Timberline 1 cu. ft. Top Soil 50055019 (38.5 lb) (read 2026-10-05)
- Lowe's listing: Earthgro 40-lb Top Soil (covers 4.5 sq ft at 2 in, i.e. 0.75 cu ft) (read 2026-10-05)
- Scotts Miracle-Gro, Miracle-Gro Garden Soil All-Purpose product page (sizes, coverage, depth) (read 2026-10-05)
Settling
Soil arrives fluffed up. It was dug, screened, dropped into a truck and dumped into a pile, and every one of those steps adds air. Once it is spread, raked and rained on, it settles, and a bed that was level with the boards in May can be an inch or two low by July. The waste allowance in the calculator is how you plan for it: 10 percent for plain screened topsoil, 15 to 20 percent for a blend with a lot of compost, and 5 percent for dense fill. Water a new bed before planting to settle it and top it up, rather than planting into soil that is about to drop. For a lawn, let the new soil settle for a week or two before seeding or sodding if you can, and fill any dips that appear.
Worked example: a lawn and two raised beds
A 40 by 30 ft area is being turned into lawn with 4 in of new topsoil, and two 4 by 8 ft raised beds are being filled 12 in deep, all with 10 percent extra for settling:
Result
| Area | Sq ft | Depth | Cubic feet |
|---|---|---|---|
| New lawn area | 1,200 | 4 in | 400.0 |
| Raised bed 1 | 32 | 12 in | 32.0 |
| Raised bed 2 | 32 | 12 in | 32.0 |
- Volume with 10% extra510.4 cu ft
- Bulk order18.9 cu yd
- Approximate weight19.9 tons
- 0.75 cu ft bags instead681
The lawn is 400.0 cubic feet on its own and the two beds add 64.0. With the allowance the order is 18.9 cubic yards, which a supplier would round to 19, weighing roughly 19.9 tons. The same soil in 0.75 cu ft bags would be 681 bags, which is a delivery no matter how you buy it.
Mistakes people make
- Ordering by the top of the bed. Measure inside the boards and stop an inch or two below the rim; soil heaped above the boards washes out.
- Top-dressing too deep. Half an inch at a time. If the lawn is an inch low, do it twice.
- Filling a planting bed with fill dirt. Fill is for grade changes. Plants want topsoil or a blend, at least in the top 8 to 12 in.
- Forgetting settling. Order the allowance, water the bed, and top it up before you plant.
- Expecting a pickup to carry a yard. Check the payload rating on the door jamb. A yard of soil is a trailer load or a delivery.
- Buying topsoil by the bag for a lawn. A few hundred square feet is already dozens of bags. Price the bulk delivery.
Frequently asked questions
How many bags of topsoil are in a cubic yard?
Divide 27 cubic feet by the bag size: 36 of the 0.75 cu ft bags, 27 of the 1 cu ft bags. Bagged topsoil is often labelled by weight (a 40 lb bag, for example) and the volume is in smaller print on the back; the calculator counts by the volume, because that is what fills the bed.
How much does a cubic yard of topsoil weigh?
For topsoil the calculator uses 78 lb per cubic foot, so a cubic yard weighs about 2,106 lb, or 1.05 tons. Wet soil weighs considerably more, and soil with a lot of compost in it weighs less. That is at or beyond the payload rating of most half-ton pickups, so a yard of topsoil is usually a delivery or a trailer load.
How much topsoil do I need for a new lawn?
Enough to give the grass 4 to 6 in of good soil to root into, counting whatever usable soil is already there. On a site scraped to subsoil by construction, that means 4 to 6 in of new topsoil; on a tired lawn being redone, 2 in of new soil tilled into the old is often enough. For the 1,200 sq ft lawn in the example above, 4 in is 14.8 cubic yards before the waste allowance and 16.3 with 10 percent added.
Can I put topsoil over existing grass?
A thin layer, yes: that is top-dressing. Spread no more than about half an inch at a time and rake it in so the grass blades show through; the lawn grows up through it within a couple of weeks and you can repeat it the next season. Anything deeper smothers the grass and you are effectively starting a new lawn, so it is better to strip or kill the old turf first.
What is the difference between topsoil, garden soil and fill dirt?
Fill dirt is subsoil: whatever came out of a hole, with little organic matter, sold cheaply for raising a grade or filling a low spot where nothing needs to grow. Topsoil is the upper, darker layer with organic matter in it; screened topsoil has had rocks, roots and clods sifted out. Garden soil and raised-bed mix are bagged blends of topsoil, compost and sometimes peat or bark, lighter and richer than plain topsoil. Use fill for bulk and depth, topsoil for lawns and the top layer, and blends for beds.
How much soil fills a 4 x 8 raised bed?
A 4 by 8 ft bed filled 12 in deep holds 32 cubic feet, which is 1.19 cubic yards; two of them need 2.37 yards, before the allowance. In bags that is 43 of the 0.75 cu ft bags per bed. Many gardeners fill the bottom half of a tall bed with coarse material or cheaper fill and only the top 8 to 12 in with the good mix.
Should I mix compost into the topsoil?
For beds, usually yes: a quarter to a third compost by volume is a common blend, and you can enter the compost as a second material in the project planner to get both quantities. For a lawn, a half-inch top-dressing of compost over the soil does more good than mixing it deep. For filling a low spot in a lawn, plain screened topsoil is better, because compost keeps settling as it breaks down.