Before you measure anything, stop and answer one question: are you filling a raised bed, or are you spreading topsoil on the ground? The two jobs look similar on a tape measure but call for completely different depths, different products and different bag counts. A raised bed wants a box filled edge to edge with something plant-ready. A lawn renovation wants a thinner layer spread on top of existing dirt and raked smooth. Mixing those two up is how you end up either drowning your grass in 12 inches of imported dirt or starving your tomatoes with 2 inches.
Measure the box, not the footprint
For a raised bed, measure the actual inner length and width of the frame - the wood walls steal a few inches on each side. Then measure how deep you plan to fill. Six inches is the minimum for greens; 12 inches is where tomatoes, peppers and most shrubs are comfortable. Once you have those three numbers in hand, the volume falls out fast.
For a lawn, you are not filling a box - you are spreading a layer. Measure the open area you are regrading, set the depth to 4 to 6 inches for a fresh seed bed, and order the volume that covers it. If you are only top-dressing an existing lawn to smooth out low spots, drop the depth to 1 or 2 inches.
The 0.75 cu ft bag math
At the garden center, the standard bag on the pallet holds 0.75 cubic feet of topsoil. A cubic yard is 27 cubic feet, so that works out to about 36 bags per yard. Stack a 10 by 10 ft raised bed at 8 inches deep - that comes to about 2.5 cubic yards, which is roughly 90 bags. Pause on that number. Ninety bags is a whole weekend of trips from the car to the backyard, and the per-cubic-foot price is several times the bulk rate.
Bulk versus bagged
For any raised bed over about 4 by 8 ft, call a landscape supplier. A cubic yard of screened topsoil runs 1.0 to 1.3 tons, so a 2.5-yard load is about 3 tons - a dump truck can drop it on your driveway in five minutes. Bagged makes sense for patching a single low spot or filling a 3 by 6 ft herb planter, where a truck minimum would double the cost.
Topsoil is not garden soil
This trips people up. Bulk topsoil is screened native dirt - fine, loamy, no fertilizer, no compost. Dump it straight into a raised bed and the plants will struggle, because there is no organic matter and no living biology. For raised beds, either buy bagged garden soil blend (which is topsoil already mixed with compost, peat and amendments), or buy bulk topsoil and mix in 20 to 30 percent compost by volume yourself.
Ordering number cheat sheet
| Project | Depth | Typical volume |
|---|---|---|
| New lawn seed bed | 4 to 6 in | 1 cu yd per 80 to 100 sq ft |
| Lawn top-dress | 1 to 2 in | thin layer only |
| Raised bed, greens | 6 in | fill the box |
| Raised bed, vegetables | 10 to 12 in | fill the box |
| Tree planting backfill | 2 to 3 in on top | never pile on trunk |
When the truck arrives, ask the driver to spread the pile near the bed but not on the lawn - a cubic yard of wet dirt weighs over a ton and leaves a permanent stain. Wheelbarrow it in, rake it level, and water once before planting so it settles to its true volume.
Topsoil Calculator
Decide whether you are filling a raised bed or top-dressing an existing lawn, measure the box, and read out yards, tons and bag count before the dump truck shows up.
How to use
- Decide the project - a raised bed, a fresh lawn, or a patch repair all want different depths
- Measure length and width in feet (or radius for a circular bed)
- Set depth - 6 to 12 inches for raised beds, 4 to 6 inches for a new lawn
- Add 5 to 10 percent for uneven ground and settling
- Read cubic yards, estimated tons and the 0.75 cu ft bag count side by side
Supported formats and limits
- Estimate only - real volume shifts with compaction and how wet the dirt is
- Weight assumed at 1.0 to 1.3 tons per cubic yard for screened topsoil
- A cubic yard holds 27 cubic feet, which is about 36 standard 0.75 cu ft bags
- US units only - feet, inches, square feet and cubic yards
Examples
A 10 by 10 ft raised bed at 8 inches deep comes to about 2.5 cubic yards, roughly 3 tons, or about 90 standard 0.75 cu ft bags.Common errors
- Length and width must both be positive numbers
- Radius must be positive for circular beds
- Depth should sit between 1 and 18 inches
- Waste factor stays between 0 and 25 percent
Privacy and browser support
No measurements leave your browser. The whole calculation runs on your own device.
FAQ
How deep should a raised bed be filled?
Six to 12 inches is the working range. Leafy greens are happy at 6 inches; tomatoes, carrots and shrubs want 12. Anything deeper wastes soil on roots that never reach the bottom.
How big is a standard bag of topsoil?
Most garden centers sell 0.75 cubic foot bags. A cubic yard is 27 cubic feet, so that works out to about 36 bags per yard. A few stores stock 1 cu ft or 1.5 cu ft bags - the tool lets you type in your bag size.
How thick should topsoil be for a new lawn?
Four to 6 inches of loose topsoil over the existing grade is the standard seed-ready bed. If you are only top-dressing an existing lawn, 1 to 2 inches is enough - more buries the existing grass.
Topsoil versus garden soil - what is the difference?
Topsoil is screened native dirt, sold by the yard, and meant to be mixed into the ground. Garden soil is a blended product - topsoil plus compost, peat and amendments - sold in bags for raised beds, where you have no native soil to mix with.
How heavy is a cubic yard of topsoil?
Screened loam runs about 1.0 to 1.3 tons per cubic yard when moderately moist. Rain-soaked truckloads can hit 1.5 tons, which matters because a half-ton pickup is rated by weight, not volume.
Can I haul topsoil in my pickup?
A half-ton pickup is rated for about 1,000 lb, which is less than one cubic yard of damp topsoil. Plan on two or three trips for a small bed, or just pay the delivery fee - dumping a full yard into the bed saves your springs.
Should I mix in compost?
Yes. Bulk topsoil is mostly mineral dirt. For a vegetable bed, blend in 20 to 30 percent compost by volume before you plant. A new lawn just needs a fine, raked surface; the organic matter builds over time with fertilizer.