Soil Calculator
Results update as you type, there is no submit button.
Enter a bed's length, width and the depth you're filling it to, and this calculator returns cubic feet, cubic yards and the number of standard 1.5 ft³ bags at once, so you can compare the bagged and bulk routes to the same order before deciding which one to actually place.
Recommended Depths by Use Case
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Standard garden beds
Enough loose depth for most vegetables and annuals to spread roots sideways without drying out fast in summer.
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Raised beds
Filled deeper since there's no native soil underneath contributing structure, drainage or nutrients.
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Lawn top-dressing
A thin amending layer worked into existing turf rather than a full fill depth.
Anything shallower than about six inches in a standing bed dries out quickly once summer heat sets in and limits root spread to shallow annuals, it's the depth worth treating as a floor rather than a target to shave down when trying to save on material.
Topsoil, Garden Soil and Potting Mix Aren't Interchangeable
"Soil" covers several genuinely different products, and using this calculator's volume figure to order the wrong one is a common mistake. Topsoil is the least processed and cheapest option, mostly mineral content stripped from a field or excavation site, useful as fill or a base layer but not reliably fertile on its own. Garden soil is topsoil blended with compost or other organic matter specifically for planting directly into, which is what most of the depth recommendations above assume. Potting mix is a third, distinct product, usually soil-free, built from peat, coir or bark for container drainage, and is priced and sold in much smaller bag sizes than the 1.5 ft³ figure this calculator uses, so don't run a large container order through this page expecting a bagged-topsoil price to apply.
For a raised bed specifically, a common recipe blends roughly equal parts topsoil, compost and a coarse aggregate like perlite or coarse sand rather than filling with a single product, the volume math is identical (you're still filling the same cubic footage), but the per-bag or per-yard cost changes considerably depending on the blend ratio you land on.
Bagged vs. Bulk: Where the Line Sits
Twenty-seven cubic feet, one cubic yard, is the rough threshold where bulk delivery starts beating bagged soil on price per cubic foot, the same threshold covered in more depth on the cubic yards calculator. Below that line, a dozen or so 1.5 ft³ bags from a garden center is usually simpler than arranging a delivery with a minimum-order fee attached; above it, calling a supplier for a bulk load is worth the phone call. This calculator's bag-count output uses the standard 1.5 ft³ bag size most garden centers stock, matching the figure already established on this site's homepage landscaping section.
If you'd rather start from a known square footage instead of measuring length and width separately, the square-feet-to-cubic-feet calculator takes an area and a depth directly to the same result.
Settling and Compaction
Two adjustments matter once your order is calculated. Bagged soil settles roughly 10–20% after watering, so a bed filled exactly to the brim on delivery day will sit noticeably lower a week later, buying slightly more than the exact calculated figure avoids a second trip for a partial bag. Bulk material delivered loose is measured before it compacts underfoot or under its own weight over time, which is why this calculator's output should be treated as a minimum for your order rather than an exact final number.
Worked example: a 4 ft × 12 ft raised bed filled to 8 inches:
4 × 12 × 0.6667 = 32 ft³
32 ÷ 1.5 = 22 bags, or about 1.2 cubic yards loose
Rounding this particular example up rather than down matters twice over, once for the settling covered above, and again because 22 bags is an odd number to split across multiple trips if a car only holds a dozen at a time. Buying the full 22 (or 23, to leave a small buffer) in one visit is usually worth the extra weight in the trunk compared to a second trip for the last two bags a week later.
Amending Native Soil vs. Full Replacement
Not every project needs this calculator's full volume ordered as new material. If the existing ground soil is reasonably workable, not solid clay or construction rubble, amending it with a few inches of compost tilled into the top six to eight inches is often cheaper and just as effective as fully replacing the bed's contents, since you're only buying the amendment volume rather than the full bed depth. Run the bed's area through this calculator at the shallower amendment depth (2–3 inches is typical for compost top-dressing) rather than the full 6–8 inch planting depth, and till it into what's already there.
Full replacement makes more sense when the existing ground is heavy clay, contaminated, or when a raised bed sits on top of a hard surface like a patio or driveway with no native soil underneath at all, in those cases, the full depth figure from the recommendations above is the number to order against, since there's nothing underneath to amend.
Delivery Access and Placement
A calculated volume is only useful if the delivery can actually reach where the soil needs to go. Bulk dump trucks typically need at least an 8–10 ft wide, clear path to the drop point and a reasonably flat, stable surface to tip the load onto, a load dumped on a slope or soft lawn can be harder to move afterward than the soil itself was to order. If a direct dump isn't possible because of fences, narrow gates or a long distance from the street, ask the supplier about a conveyor or blower truck, which can place material considerably further from the truck than a straight tip can, usually for an added fee worth confirming before the delivery date rather than after the truck arrives.
For smaller volumes near this calculator's bagged threshold, splitting a bulk order into several smaller drop points around a property, rather than one large pile that then has to be wheelbarrowed everywhere, is often worth the minor added delivery complexity, especially for beds on opposite sides of a house.
Frequently Asked Questions
Should I buy topsoil in bags or order it in bulk by the yard?
Under roughly 27 cubic feet (one cubic yard), bagged soil is usually cheaper and easier to handle without equipment; above that threshold, a bulk delivery wins on price per cubic foot even after accounting for the minimum-order fee most suppliers charge.
How much will my soil order settle after it's watered in?
Plan for roughly 10–20% settling once bagged or loose soil is watered and beds down, a bed filled exactly level on delivery day will typically sit noticeably lower within a week or two. Ordering slightly more than the calculated volume, or topping off the bed after the first watering, avoids a second delivery.
Is bulk topsoil measured before or after it's compacted?
Before, loose bulk material is measured by volume as delivered, not after it settles or gets walked on, which is exactly why treating a soil calculator's output as a floor for your order (round up) rather than a ceiling avoids running short.
Do raised beds and in-ground beds need different depths?
Raised beds typically get filled to their full height (often 10–12 in) since there's no existing soil beneath contributing nutrients or drainage; in-ground beds usually only need 6–8 in of amended topsoil worked into the existing ground. This calculator's depth field accepts whichever figure matches your actual bed type.