The volume half of this calculator is exact. Twenty-seven cubic feet to the cubic yard is a definition, and 324 divided by your depth in inches gives the square feet one yard covers. Those numbers are arithmetic and need no source.
The weight half is deliberately different, and it is the reason this page exists.
Why there is no single answer for weight
Ask any other calculator what a cubic yard of topsoil weighs and it will tell you a number — 2,200 lb, or 2,700, or 1 ton, stated flatly. That number is wrong for most people who read it, and the reason is worth understanding because it changes what you should do.
No extension service publishes a weight for a yard of delivered topsoil. Not because nobody has measured it, but because it is not a property of soil. It is a property of one supplier's pile on one particular day: how much organic matter is in that batch, how finely it was screened, how long it has sat, and above all how wet it is. Water is heavy, and the same soil after a week of rain can weigh a third more than it did dry.
What is published is two different things, and this calculator keeps them apart:
Compost, by weight per cubic yard, as supplied. Oregon State University Extension's EM 9217 gives about 1,000 lb per cubic yard as a rule of thumb for screened compost at 50% moisture, with the full range from 800 to more than 1,600 depending on moisture, particle size and compaction, and very wet composts exceeding 1,500 on their own. That is a real answer to a real question, and it is a range because the material genuinely varies by a factor of two.
Soil, by texture, in grams per cubic centimetre, for soil in place. The USDA Natural Resources Conservation Service publishes ideal and root-restricting bulk densities for each soil texture — the density below which roots grow well, and the density above which they are restricted. A well-structured clay sits below 1.10 g/cm³, which is about 1,854 lb per cubic yard; a sandy loam can reach 1.80 before roots struggle, which is over 3,000.
But that table describes soil in the ground. Undisturbed, settled, in situ. It is not the same material as loose screened topsoil tipped onto a driveway, which is looser and lighter for the same texture. So for delivered soil those figures are an upper bound, not an estimate — and the calculator says so rather than converting them into a false precision.
The NRCS table also does not apply to red clayey soils or to soils formed from volcanic ash, which is stated in the publication and worth repeating rather than quietly extending.
What to do when the weight actually matters
Three situations where getting it wrong has consequences, and in all three the answer is the same:
- A truck payload. You will hit the weight your vehicle is rated to carry well before you fill the bed. Enter your bed capacity above to get the number of trips by volume, then check the payload figure for your specific vehicle — and tell the supplier what you are driving, because they load to weight.
- A floor or balcony loading. A raised bed on a roof terrace or balcony is a structural question, and a range from a calculator is not the input for it.
- A large order priced by the ton. Some suppliers sell by weight rather than volume, which means the wetness of the pile on delivery day changes what you get for your money.
In every one of those cases: ask your supplier what their material weighs. They handle it daily and they know. That is not a failure of this calculator — it is the correct answer, and no calculator that prints a single number can give it to you.
How to use it
- Give the area. Length and width in feet, or the total square footage if you already know it. Metric works throughout with the toggle.
- Give the depth. Three inches is a typical topdressing over an existing bed; six or more for a new one. Depth is what most people underestimate, and it scales the answer linearly.
- Pick the material. Compost has a published weight per cubic yard; soil has a texture-based range with the in-place caveat. The choice changes the weight only, never the volume.
- Add your truck capacity if you are hauling it. Measure the bed rather than trusting a figure: length × width × the depth you would actually load to, in feet, divided by 27.
The result gives cubic yards and cubic feet, what one yard covers at your depth, bag counts at the four sizes bulk material is sold in, and the weight range with its source.
Bulk or bags
The crossover is around eighteen bags. Past that, a cubic yard delivered loose is almost always cheaper per unit volume than the same material in bags, and it is one trip instead of a car full. Below it, bags win on convenience and on not having a heap on the driveway.
Bag sizes here are 0.75, 1, 1.5 and 2 cubic feet, which is how bulk soil, compost and mulch are sold. Potting mix is different — it is sold in US dry quarts, not cubic feet, and the difference catches people out. The soil volume converter handles that conversion, and how much is a yard of dirt works through the bulk-versus-bags arithmetic with the costs laid out.
Related calculators
- Raised bed soil calculator — the same volume sum for a bed with sides, including round beds, with bag counts at whatever size your shop sells.
- Soil volume converter — dry quarts, cubic feet, liters and cubic yards, both ways.
- Mulch calculator — the same arithmetic at mulch depths.
- How much is a yard of dirt — what a cubic yard looks like, how far it goes, what it weighs, and whether it fits in a pickup.