The Short Answer, and Why It Is a Range
Plan on losing somewhere around 10 to 25 percent of the volume between the pile sitting in your driveway and the finished surface once the soil is spread, watered, and left alone for a few days. Plain screened topsoil sits at the low end of that range. Compost heavy garden mixes sit at the high end.
The usable version, the one you can do in your head before you call a supplier, looks like this. Take the cubic yards you measured, multiply by 1.10 to 1.25 depending on how much organic matter is in the mix, then round up to the nearest increment your supplier actually sells in. That is the whole method. Everything below is just explaining which end of the range you belong on and why.
The range is not us hedging. It covers two completely different processes that happen at two completely different speeds, and they call for two different responses. One you pad for at order time. The other you handle with a bag or two of amendment next spring. Once you can tell them apart, the number you multiply by stops being a guess.
One thing worth saying plainly before anything else. Settling is not the supplier shorting you. A cubic yard of soil is measured loose in the loader bucket, the same way it is measured at every yard in the country. Nobody is selling you compacted volume, and nobody could, because the amount a given load compacts depends on what you do with it after it leaves the truck.
Two Different Things People Call Settling
When a homeowner says their soil settled, they usually mean one of two things without realizing there is a difference. Sorting this out is the single most useful thing in this article.
Mechanical compaction, days one through three
This one is just air leaving. Freshly screened soil is riddled with voids. The screen breaks clods into crumbs and throws air between them, the loader bucket lifts and drops the material a few more times, and by the time it hits your driveway a meaningful share of the pile is empty space held open by the shape of the crumbs.
Water collapses that. The first deep soaking, or the first honest rain, lubricates the particles enough that they slide into the gaps between each other and the surface drops. Nothing has disappeared. The same soil is simply occupying less room because it is no longer propped open.
This happens fast, which is why so many people describe the exact same weekend. The bed looked perfect Saturday afternoon, it rained Tuesday, and by the following Saturday the soil line sat two or three inches below the top rail. Most of the mechanical settling is done within a few days of the first real wetting, and essentially all of it is done inside the first few weeks.
This is the part you pad for when you order. It is predictable, it is over quickly, and once it has happened it does not happen again.
Organic matter breakdown, months and seasons
The second kind of settling is material genuinely leaving the bed. Compost, leaf mold, aged bark fines, and peat in a blended mix are food. Soil organisms consume them, and the volume those materials occupied goes away over a growing season or two. There is nothing to collapse into, because the stuff is gone.
This process is slower, and more importantly it does not stop after one round. A compost rich raised bed keeps dropping year after year, at a declining rate, until what is left is mostly the mineral fraction. That is not a defect in the mix and it is not something you did wrong. It is the reason experienced gardeners top off their beds every spring as routine maintenance, the same way they sharpen a pruner or clean a birdbath.
Key takeaway: mechanical compaction is an ordering problem, so pad for it now. Organic breakdown is a maintenance problem, so handle it with an annual compost top up rather than buying an enormous surplus today and letting it sit in a heap behind the shed.
Fluff Factor, or Why the Pile Looks Bigger Than the Job
Contractors have vocabulary for this that homeowners rarely hear. Material that has been dug, screened, and dumped is measured in loose cubic yards. Material sitting at finished grade, packed down, is measured in compacted or in place cubic yards. The gap between those two figures is what the trade calls the fluff factor, and bulk soil is always sold loose.
Screening creates most of the fluff. Take soil out of the ground, where it has been sitting under its own weight for decades, push it through a screen, and you have broken every clod apart and mixed air into all of it. The same dirt occupies noticeably more room after screening than it did before. Nothing was added. It was just aerated.
Weight is the easiest way to feel this if the concept stays abstract. Screened loam and premium topsoil generally fall somewhere around 2,000 to 2,400 pounds per cubic yard, and that same material weighs less per yard loose than it does once packed in place, because a loose yard is partly air by volume. If a yard of soil is lighter than you expected, some of what you are buying is space between the crumbs.
Moisture complicates it in both directions. Wet soil is heavier and it packs tighter, so a delivery that arrives after a rainy week settles harder once you spread it. Bone dry screened soil, on the other hand, looks enormous on the driveway and shrinks visibly the first time a sprinkler hits it. Neither one means you got a bad load. It just means the pile you are looking at is a poor guide to finished volume.
The last piece follows from all of it. High organic content means lighter, fluffier, more air by volume, and that is exactly the material that also loses volume to decomposition later. Compost heavy mixes get hit by both mechanisms, which is why they sit at the top of the settling range instead of the middle.
Padding Your Order by Project Type
The right buffer depends on what the soil is going to do for a living. Here is how the three common cases break down.
Raised beds and garden boxes
For a standard blend of topsoil with compost and amendments, add roughly 10 to 15 percent to your measured volume. For a high organic mix that is largely compost, go 15 to 25 percent, and go into it expecting to add a couple of inches of compost each spring for the life of the bed.
Raised beds carry a second trap that has nothing to do with math. People fill flush to the top rail, admire it, water it, and then lose several inches. Fill slightly proud of the rail instead, mounding the soil a little above the frame, then soak it thoroughly and see where it lands before you decide you are finished. A bed that starts an inch high and ends level is a bed you did right.
Lawn topdressing and low spot repair
Topdressing is a thin layer over an existing surface, often a half inch to an inch worked into the turf. There is very little depth available to compress, so a modest buffer is plenty here. Rounding up to the next increment your supplier sells usually covers you on its own.
For this job the bigger risk runs the other way. Over ordering for a topdressing project leaves you with a pile you have nowhere sensible to put, and topsoil does not keep well sitting in the open growing weeds. Measure the actual square footage, keep the layer thin, and resist the urge to pad heavily.
Grade fill and bigger earth moving
Fill work is the opposite situation entirely. When you are raising a grade, backfilling behind a wall, or building a base under a hard surface, you are deliberately compacting the material in layers. You want it dense. That means the drop from loose delivered volume to finished compacted volume is substantial, well past what a garden bed loses, and it should be padded generously.
If a plan or a contractor spec gives you a volume, find out whether that number is loose or compacted before you order. Ordering loose yards against a compacted spec is one of the most common ways a fill project ends up short on the last day.
One practical note that applies to all three. Suppliers sell bulk topsoil and garden soil in set increments, often half yards or full yards, so once you have added your buffer, round up to the next increment rather than shaving down to the one below. A partial extra yard costs a fraction of what a second delivery costs.
Doing the Math Without Overthinking It
Here is one example carried all the way through. Say you are building a raised bed with an inside measurement of 8 feet by 4 feet, and you intend to fill it 10 inches deep.
- Convert the depth to feet. 10 inches divided by 12 is about 0.83 feet.
- Multiply the three dimensions. 8 times 4 times 0.83 is about 26.6 cubic feet.
- Divide by 27 to get cubic yards. 26.6 divided by 27 is about 0.99, so call it 1 cubic yard in place.
- Apply the buffer. You are using a topsoil and compost blend, so multiply by 1.15. That gives about 1.14 cubic yards.
- Round up to the increment your supplier sells. If they sell in half yards, order 1.5 yards.
Scale it and the logic holds. Four beds of that size is about 4 cubic yards in place, 4.6 with a 15 percent buffer, and you order 5. If those beds are getting a mostly compost mix instead, use 1.25 as the multiplier and order 5.5 or 6.
Two measuring mistakes account for most of the shortfalls we hear about. The first is using the outside dimensions of a raised bed instead of the inside. On a small bed built from two by ten lumber, board thickness eats real volume, and a couple of inches gone from each dimension adds up fast on a 4 by 4 box.
The second is depth dishonesty, and it is usually accidental. People say six inches when they are building eight. Or they plan to fill a tall bed only partway, then get out there, decide a half empty box looks silly, and fill it to the top. Measure the depth you are actually going to fill, not the depth you told yourself you would settle for.
Ordering a little long is cheap insurance, because surplus soil always finds a home. Low spots in the lawn, thin patches around foundation plantings, the gap behind the shed where nothing grows anyway. A leftover half yard is a minor inconvenience. Being a half yard short with the tiller already returned is a lost weekend.
How to Settle Soil On Purpose Instead of Waiting for Rain
You do not have to find out how much your soil settles by discovering it later. For anything that is going to grow plants, water is the right tool. Fill the bed, soak it thoroughly and deeply, let it sit a day, then come back and top it off. You get the settling over with before you plant instead of after, and you avoid the awkward job of adding soil around established seedlings.
Do not tamp garden soil and do not drive equipment across it. Collapsing air pockets with water is fine. Crushing the structure with a tamper or a plate compactor is not, because the same pore space that holds air also holds water and gives roots somewhere to go. A plate compactor in a vegetable bed is a genuine mistake, not a shortcut.
Tamping in lifts is correct for the other job. Fill under a patio, a walkway, a retaining wall, or a grade change should go in shallow layers with each layer compacted before the next one goes on. Dumping the whole load and hoping is how you end up with a settled dip under pavers two summers later.
A couple of timing notes. Order and spread when the material is workable rather than sopping wet. Very wet soil is heavy to shovel, and it smears and clumps instead of crumbling, which makes grading a thin layer miserable. And after you top off a finished bed, mulch the surface. It cuts down on crusting and keeps the fine top layer from washing down into whatever voids remain.
How We Started
We started Mulch Mound because we got tired of the hassle that came with buying landscaping materials. The options were either loading bags into your car at a garden center or calling around to local suppliers, trying to figure out pricing, minimums, and delivery schedules. Neither option felt convenient or transparent.
Three of us – Alec, Mo, and Tyler – decided there had to be a better way. Alec and Tyler got their start back in 2013 running a landscaping business during college, moving mulch and mowing lawns to pay tuition. That experience taught them how frustrating it was to source materials, and years later, that frustration turned into Mulch Mound.
We focus on making it simple to get mulch, stone, and soil delivered directly to your home. Order online, pick your delivery date, and we handle the rest. No loading bags. No calling multiple suppliers. No wondering if you bought enough or paid a fair price.
We work with quality local suppliers in the areas we serve and aim to be straightforward about what we offer and what it costs. Landscaping is hard work. Buying the materials for it shouldn't be.
Frequently asked questions
Why did my raised bed sink a few inches right after the first watering?
Screened soil holds air between its crumbs, and those crumbs are propping each other open. Water lets them slide past one another into the gaps, so the whole column shortens. A bed that drops evenly across its whole surface is behaving exactly as expected, and topping it off once is the end of the story.
Uneven sinking is a different signal. If one corner or one strip drops far more than the rest, something under the soil usually gave way. Common culprits are an old stump or root mass rotting out, a rodent tunnel collapsing, or a base layer of cardboard, branches, or leaves that broke down faster than the soil above it could bridge. Dig into the low spot before you just keep filling it, otherwise you will be filling it again next year.
Does compost heavy soil settle more than plain screened topsoil?
Yes, and for a reason worth understanding. Mineral particles, the sand, silt, and clay in topsoil, do not disappear. They can be packed tighter, but the material itself stays put indefinitely. Organic matter is different. It is being eaten, and what gets eaten leaves the bed as carbon dioxide and water.
So a mostly compost bed loses volume twice, once to compaction in the first week and again to decomposition across the season. The practical upshot is not to buy a huge surplus on day one. It is to accept that this kind of bed wants a couple of inches of compost added each spring, and to budget for that small recurring order instead of one giant delivery you have to store.
What is the difference between loose and compacted cubic yards?
Loose cubic yards describe material as it sits after being dug, screened, and dropped, full of air. Compacted or in place cubic yards describe the same material once it is packed at final grade. Supplier quotes and truck capacities are stated loose, because that is the state the material is in when it changes hands.
For a garden bed the distinction is mostly academic and the buffer handles it. On fill work it matters a great deal, because a plan or an inspector may call for a compacted volume or a compacted depth. If you are working from a spec sheet rather than a tape measure, confirm which basis the number uses before you order anything.
Should I water it in or tamp it before topping off?
Decide by what the soil will eventually support, not by how much of a hurry you are in. Anything that will grow plants gets water, full stop. Beds, borders, lawn repairs, planting holes. Anything that will support a hard surface or hold a grade gets tamped in lifts. Paver base, walkway subgrade, backfill behind a wall.
The reverse of either one causes real problems. Tamping a planting bed gives you a dense layer roots struggle through. Relying on rain alone to settle fill under pavers gives you a sunken patio. There is no project where you should split the difference.
What if I already ordered and came up short?
First, see whether you can combine the gap with something else you need. If mulch, compost, or stone is on your list for this season anyway, ordering it together with the extra soil spreads the trip cost across more material instead of paying it for a single partial yard.
For a genuinely small gap, a few bags may be the cheaper answer even though bagged product costs more per unit volume. Minimum delivery charges make very small bulk orders disproportionately expensive, and that math flips somewhere around a fraction of a yard. If the shortfall is larger than that, take the second bulk delivery and order it a little long this time.