Raised Bed Soil Calculator
Find the exact cubic feet of soil mix your bed needs.
Use ToolFree calculator
Topsoil Calculator
Cubic yards or bags of topsoil for beds, lawns and grading.
Topsoil Calculator
Chlorova · updated for 2026
Calculator
Quick samples
Click “Calculate” to see your results.
Buy screened, tested topsoil for beds; 'fill dirt' is a different product. Order 10–15% extra for spreading and compaction — and never use construction-fill soil in food gardens.
The topsoil calculator sizes any soil purchase the way the landscape yard rings it up: square feet × depth ÷ 12 for volume, ÷ 27 for cubic yards, then a bag count for the ones sold in 0.5-cu-ft and 13.5-cu-ft (half-yard) bags. Regrading a lawn at one inch over 1,200 square feet is 100 cubic feet — barely four bags — while a new 4x8 bed at eight inches wants almost nine. Depth is the input that changes everything, so measure it where the ground actually is, not where you wish it were.
How to Use the Topsoil Calculator
- Measure the length and width of the area to be filled or raised, in feet.
- Enter the average depth of soil needed — probe at several spots and average low spots with high ones.
- Set the bag size to what your supplier stocks: 13.5 cu ft (half yard) and 2 cu ft are common.
- Type the local price per bag so cost appears beside the count, then compare against the bulk yard price.
- For new beds, decide whether you are filling the whole volume with topsoil or half with cheaper fill below grade.
- Press Calculate and add ten percent on the bag run for spread waste and settling.
The Topsoil Formula, Explained
Pure volume math: cubic feet = length × width × depth ÷ 12, and cubic yards = cubic feet ÷ 27 because a yard is 3 × 3 × 3 feet. Bags = cubic feet ÷ bag size, rounded up since half a bag does not exist at the register.
The human factor is settling: delivered topsoil compacts 10 to 15 percent under its own weight and the first rains, so a 4-inch spread finishes nearer 3.5. Pros order the target depth plus that shrinkage, or spread a little high and let water do the packing. Depth choice follows the use — a quarter to half inch is a lawn top-dress, one to two inches levels a low spot, four to six builds a flower bed, and eight or more is raised-bed territory where the bed calculator's three-part blend mix applies instead.
Worked Example: Building a 20x4 Flower Bed
- The new bed is 20 × 4 = 80 square feet, filled to an average 6 inches.
- Volume: 80 × 6 ÷ 12 = 40 cubic feet — about 1.5 cubic yards.
- In 13.5 cu ft bags: 40 ÷ 13.5 = 2.96, so 3 half-yard bags.
- In 2 cu ft garden-center bags the same job is 20 bags — the per-cubic-foot price usually doubles on that swap.
- Bulk at $45 per yard delivered (plus a common $75 delivery minimum) lands near $140; three bags at $9 is $27 hauled in a truck.
- Under two cubic yards, bags win unless you already own a truck and strong backs.
- Add the settling cushion: spread 6.5 to 7 inches to finish at a true six after the first soaking.
Common Uses and Their Depths
Depth is the whole decision. These are the typical asks, with the honest note for each. Multiply your own square footage against the depth and the calculator does the rest.
| Job | Typical depth | Note |
|---|---|---|
| Lawn top-dressing | 0.25–0.5 in | Compost usually, not plain topsoil |
| Lawn leveling low spots | 1–2 in | Never bury crowns deeper than 2 in |
| New flower bed | 4–6 in | More if subsoil is compacted — double dig |
| Raised bed fill | 8–12 in | Use the 50/30/20 bed mix, not pure topsoil |
| Grade build-up for drainage | 2–6 in | Compact in layers or it sinks unevenly |
Key Terms
- Screened topsoil
- Sifted to remove rocks and debris — the product worth paying extra for in planting areas.
- Fill dirt
- Unscreened subsoil for grade changes under turf or beds; it compacts hard and is not a planting medium.
- Cubic yard
- 27 cubic feet — the bulk delivery unit; one yard covers 135 sq ft at 2 inches or 67 at 4.
- Settling
- The 10–15% volume loss as delivered soil compacts under rain and gravity; order the depth plus shrinkage.
- Top-dressing
- A thin (quarter- to half-inch) spread over established turf to level and feed without smothering.
What This Means in a Real Job
- Ask what is IN the topsoil: cheap 'soil' from a excavation site can be subsoil, debris or construction fill — for beds, buy from a supplier who can name the source.
- The depth number is where budgets are made or lost: going from 2 to 4 inches doubles the price, and low spots make an average depth lie — measure the shallow and deep corners separately.
- Delivery logistics decide bag-versus-bulk more than unit price: a dirt contractor drops a yard pile where the truck can reach; if it cannot, bag hauling or a pump-away line may cost more than the soil.
- For food beds, plain topsoil is the base, not the recipe — blend it with compost and aeration material using the raised bed soil calculator's mix.
- Call 811 before any digging over 12 inches, and check utility easements before having a dump truck park on a sewer line.
Common Mistakes & Fixes
- Ordering at 'target depth' and forgetting the 10–15% settling shrink — spread high and let the first soaks finish the grade.
- Using construction-site fill in planting beds, where it compacts into brick — that dirt is for building up grades under the lawn root zone.
- Buying bagged at 1 cu ft when the job is over two yards — the per-yard price of bags can triple bulk, so run both columns before the cart fills.
- Top-dressing lawn more than 2 inches deep, which smothers grass instead of leveling it; deep low spots want sod laid over the fill, not soil piled over turf.
- Skipping compaction on deep grade fills — unbuilt soil laid 6 inches at once sinks unevenly and cracks new pavement or re-exposes foundations.
When to Use This Estimate (and When Not To)
Any flat area filled to an average depth fits this math: beds, lawn regrading, filling around new patios before sod, or sizing a load for the truck. It does not fit enclosed raised beds with three-part soil mixes — the raised bed calculator handles the blend volumes — and it is the wrong tool for materials priced by weight, like stone, where the landscape rock calculator's tonnage conversion applies. Irregular beds work best as two or three overlapping rectangles summed together rather than one hopeful average.
Topsoil Calculator: Frequently Asked Questions
How much is a cubic yard of topsoil, really?
Bulk screened topsoil typically runs $40–$75 delivered regionally, often with a delivery minimum near one to two yards. Bagged it is usually $6–$12 per 13.5 cu ft half-yard bag — fine for small jobs, expensive past about two yards.
Is bagged or bulk topsoil cheaper?
Bulk wins per cubic foot almost always; bags win on total job cost under roughly two cubic yards once delivery minimums and hauling effort are priced in. A pickup truck changes that crossover point dramatically.
Should I buy topsoil or compost for my bed?
They do different jobs: topsoil is the mineral bulk that builds height and grade, compost is the living amendment that feeds it. New planting beds generally want a blend — the classic raised bed mix is 50% topsoil, 30% compost, 20% aeration material.
How deep should topsoil be over fill dirt?
Four to six inches of workable topsoil is the practical minimum for turf and ornamental roots, with more for vegetables. Below that, the compacted fill subsoil still controls drainage and root depth, so double-dig or raise the bed if the fill is heavy clay.
Do I need to account for the soil settling after delivery?
Yes — order 10–15% more than the arithmetic says, or spread 0.5 to 1 inch above target grade and let rain and light traffic compact it before planting. Large grade fills should be mechanically compacted in layers instead of free-settled.
Can I use topsoil to level my lawn without re-sodding?
For up to about an inch over established grass, yes — top-dress in passes no deeper than half the blade height so the crowns breathe. Deeper low spots should be filled first and re-sodded or reseeded rather than burying live turf under inches of soil.
Sources & Further Reading
- Topdressing and Seeding Lawns — University of Minnesota Extension. Depth limits for top-dressing established turf.
- Soil Testing for Landscapes and Gardens — Iowa State University Extension and Outreach
- Building Soils for Healthy Plants — Penn State Extension
Chlorova Gardening Team
Builds, checks and documents every tool we publish
Chlorova editorial review
Checked against extension-service publications
Formula verified against published references · Updated