Soil Calculator: Yards for Beds, Planters and Tired Ground
Enter your project dimensions
A raised bed goes in because the ground underneath it will not do the job. On the heavy clay of the southeast lake plain that means drainage. On the sandy outwash of the west side it means holding water for longer than a day. Either way the frame is a container, and a container takes more than it looks like it should, so the measuring is where an order is won or lost. Start there, before the soil calculator sees a number.
Measuring inside the frame, not around the outside of the boards
Take the inside dimensions. A bed built from two-by-tens loses three inches of width and three of length to the boards, which sounds like nothing until you run it: a nominal 4 by 10 frame is really about 3.75 by 9.75 inside, and on a foot of depth that is an eighth of a cubic yard per bed, or better than a third of a yard across three, that you would have ordered and then had nowhere to put.
Depth is the inside height you actually intend to fill, measured from the base of the frame to an inch or so below the top rail. Beds are filled proud and then settle, so that last inch is not spare capacity, it is the allowance.
Round planters and stock tanks are measured across the opening. A tank narrows toward the bottom, so the circle option will read slightly high, which on a planter is the right way to be wrong.
Three beds, a stock tank and one total
The form takes a rectangle, a circle by its diameter, or up to five separate areas totaled in one run. Three beds and a tank is four areas, which is one calculation rather than four scraps of paper.
Measurements go in feet and depth goes in inches, anywhere from 0.25 to 24. Choose the material so the ton figure matches what you are ordering, then decide on the optional checkbox that adds 5 percent for compaction and spillage. It starts ticked, and adds nothing if you untick it. Cubic yards, tons and cubic feet all come back together, and the estimate can be emailed rather than copied down.
Three hypothetical beds at 4 by 10, filled 12 inches, taken at their nominal sizes here for clarity rather than the inside figures above:
- 4 x 10 = 40 square feet each, 120 square feet for the three
- 120 x 12 / 12 = 120 cubic feet
- 120 / 27 = 4.44 cubic yards
- 4.44 x 1.0 = 4.44 tons
- with the allowance ticked: 4.67 cubic yards
A 6-foot stock tank alongside them, filled a foot deep, adds about 28.3 square feet and a further 1.05 cubic yards. Call the whole lot five and a half yards and keep the remainder for topping up.
Four inches to amend, six for a new bed, twelve to fill a frame
The depth you type is set by what the soil has to do:
- Amending a bed that already exists: 2 to 3 inches of garden soil worked through the top 6 inches of what is there.
- A new in-ground bed: 6 inches, blended into the native ground below rather than left as a distinct layer.
- An empty raised frame: 12 inches, or the inside height if it is shallower.
- A planter or a tank: whatever the container holds, up to the 24 inches the depth field accepts.
Roots move more easily through a gradual change than across a hard line, which is why in-ground beds get the soil mixed in and raised frames do not.
Garden soil is the lightest thing on the truck at 2,000 pounds a yard
Square feet times depth in inches, divided by 12, gives cubic feet. Divide by 27 for cubic yards. Multiply by the weight for tons, and blended garden soil is about 2,000 lb a cubic yard, which is a neat 1.0 ton. Screened topsoil runs about 2,200 lb, or 1.10, and fill dirt about 2,400, or 1.20. Those are the site's own approximate published figures, and the gap between them is organic content: the more compost in the blend, the lighter the yard.
Soil is ordered by the cubic yard here, so the tonnage is there to tell you what is coming off the truck rather than what to type into the quantity box. Read backwards, a cubic yard covers 162 square feet at two inches, 81 at four, 54 at six and 27 at a foot.
The split between the tools is the job rather than the product name. Bed and planter work is sized here. Lawn work and finish grading go on the topsoil tool, and raising ground on the dirt tool. Ordering against the wrong one costs you a season.
Filling a tall bed without buying depth the roots never reach
Beds built higher than about 18 inches are a different calculation. Vegetables root in the top 8 to 12 inches, so that band is the part that needs blended soil. Below it, fill dirt or coarse organic material left to break down will do, which is why the tool gets run twice on the same footprint at two different depths.
A 4 by 8 frame 24 inches deep holds 64 cubic feet, or 2.37 cubic yards, in total. Split it and the top foot is 1.19 yards of garden soil with the same again of fill dirt underneath. The footprint never changed. The order did.
Whatever goes in, it will drop. Compost-rich blends settle 10 to 20 percent as the organic fraction breaks down, most of it in the first few weeks. Fill slightly above the rail, water it in properly, then top up once rather than trying to guess the settlement up front.
Working blended soil through clay or sand instead of replacing it
Replacing a whole bed is rarely the right answer. Clay holds water too long, sand lets it go too fast, and both improve the same way: 2 to 3 inches of compost-blended soil worked through the top 6 inches, repeated over a couple of seasons. Across 200 square feet that is 50 cubic feet, 1.85 cubic yards, and about a third of what full replacement would take.
Timing suits Michigan for once. Beds can be filled and amended from the moment the ground has thawed and dried enough to work, well before base and drive work is practical, and again in fall after everything is cut back.
When the yardage looks right, take it to the product page, or browse bulk soils in the catalogue if more than one material is going on the order, set a quantity and a date, and finish at checkout, where delivery is arranged from the ZIP code you enter and how the drop is arranged covers the access. Ask for the drop on a tarp if it is landing on a drive, since bulk soil stains concrete, and pick a spot the wheelbarrow can reach without crossing a bed you have just filled.
Common questions
The beds dropped an inch over winter. What do I order to bring them back up?
Just the inch. Take the combined square footage of the beds and run it at a depth of 1, which for three 4 by 10 frames is 120 square feet, 10 cubic feet and about 0.37 cubic yards. That is a small order on its own, so it is usually worth combining with mulch or with a bed you were going to build anyway.
I ran out with the last bed half full. Is a second small order worth making?
It is, but it is worth avoiding. A half-filled frame cannot be planted and a small top-up load is a whole delivery for very little material. Round the first order up to the next half yard instead, since any excess goes straight into pots, into the lawn's low spots, or into the bed you top up next spring.
Blended soil settles. Does the estimate allow for that?
No, and it should not. The tool returns the volume of the space you described, which is the right number to order. Settling happens afterwards, in the bed, and is handled by filling proud and topping up once rather than by inflating the order. The 5 percent checkbox covers spillage, not settlement.
The tool gave me yards. Do I order garden soil, topsoil or fill dirt?
Garden soil if something is going to grow in it, which covers beds, planters and amending. Screened topsoil if you are finishing a grade or seeding a lawn. Fill dirt if you are raising ground and the surface will be finished with something else on top. The yardage is the same for all three; only the weight and the use change.
Where should a soil load be dropped if the beds are in the back yard?
As close to the gate as a truck can safely reach, on a tarp, and with the wheelbarrow route planned before the delivery rather than after. Bulk soil is heavy and wet soil is heavier, so a drop that is 30 feet nearer the beds is worth more than any amount of good intentions on the day.
Related calculators
Beds measured? Soil's a click away.
Garden soil, topsoil and fill dirt by the yard, free delivery included.
