Order for the finished depth, not the delivered depth
Loose soil is full of air. Screened topsoil comes off the pile aerated, a compost blend even more so, and both of them lose height the first time they are watered and then again through the first freeze and thaw. Ten to twenty percent is the usual drop for a screened or blended product; a dense, moist, unscreened fill dirt moves less than that, and a peat-heavy potting blend can move more.
The practical consequence is that a raised box filled level to the rim on delivery day is two inches down by the following month, which looks wrong and leaves the top of the soil below the level where you wanted the plants. The fix is to work backwards: decide the depth you want after settling, add the allowance, and order that. Overfilling deliberately, in other words, rather than being surprised.
Why the tonnage is a range
Soil is sold two ways and they do not line up. Landscape yards frequently price by the ton because that is what the scale at the gate measures, but they quote customers in cubic yards because that is what people can visualise, and the conversion between them is the one number that moves the most.
| Material | Common range per cu yd | What shifts it |
|---|---|---|
| Screened topsoil | about 2,000-2,700 lb | Moisture above all, then clay content |
| Garden or raised-bed blend | lighter, varies widely | Proportion of compost, bark and peat |
| Compost | lighter than topsoil | How finished it is, how wet |
| Fill dirt, unscreened | heavier than screened | Rock and clay content |
None of those are constants and none of them should be treated as a specification. The same pile weighs meaningfully more on Monday than it did on Friday if it rained over the weekend, and you pay for the water. This is not a reason to distrust the yard — it is simply how the material behaves. It is a reason to ask them directly: what conversion do you use between tons and yards for this product? They will have an answer, and it will be better than any figure a calculator can supply.
Raised beds are the case where bags might win
A 4 by 8 box at 12 inches is 32 cubic feet, which is 1.19 cubic yards, or 32 one-cubic-foot bags. That is genuinely on the boundary: it is a big enough number that bags are expensive and small enough that a bulk delivery has a minimum load and a delivery fee attached to it, and you may not want a yard and a half of soil sitting on your driveway to move by the bucket.
Two or three boxes changes the answer decisively toward bulk. So does having somewhere sensible to tip it. One box, with no driveway and a narrow gate, is a bag job even at the worse price.
What a fill calculation cannot decide
Every figure on this page is geometry — area times depth, adjusted for air. It has nothing to say about whether the soil you are buying is any good, which is the question that actually determines whether the bed works. Screened does not mean fertile, topsoil is not a regulated term, and material from a construction site can arrive full of weed seed, herbicide residue or subsoil clay. Look at it before it is tipped where you want it, and if you are filling a large volume, ask where it came from.
Questions people ask
How many cubic yards of topsoil do I need for 1,000 square feet?
It depends entirely on the depth. At 1 inch it is 3.09 cubic yards, at 3 inches 9.26, at 6 inches 18.5. The arithmetic is square feet times inches divided by 324 — that shortcut folds together the twelve inches to a foot and the 27 cubic feet to a yard, and it is worth remembering. Add the settling allowance on top of whatever that gives you if the depth is one you need to still be there in a month.
How many tons is a cubic yard of topsoil?
Somewhere around one to one and a third tons for screened topsoil, and the spread is real. The common quoted range is 2,000 to 2,700 pounds per cubic yard, so a yard is roughly a ton when dry and noticeably more when wet, because water is heavy and soil holds a lot of it. Anyone giving you a single figure to two decimal places is quoting a convention rather than measuring your material. The supplier who is loading it knows what their pile is running at this week, so ask them.
What is the difference between topsoil, garden soil and fill dirt?
Fill dirt is bulk material for making up levels, usually subsoil, often with rock and clay in it, cheap and not intended to grow anything. Topsoil is the upper layer stripped from somewhere, screened to remove rocks and roots, and its quality varies enormously by source — it is not a graded product. Garden soil or raised-bed mix is topsoil or sand blended with compost and bark for structure and fertility, is much lighter per yard, and settles more. For a deep fill the usual approach is the cheap material low down and the good material in the top six to twelve inches where roots live.
Should I add the settling allowance for a lawn repair?
Yes, and pay attention to it, because on a lawn the consequence is visible for years. Soil dropped into a low spot and seeded settles further than the surrounding established ground, and what looked flat in spring is a dish by autumn. For levelling work, either compact the fill in layers as you place it and water it in, or deliberately crown it slightly proud and let it settle to level. Ten to fifteen percent is a reasonable allowance for screened soil placed loose.