Free calculator
Topsoil Calculator: Cubic Yards, Bags & Raised Bed Soil
Bulk topsoil is priced by the cubic yard, bags are priced by the cubic foot, and your project is measured in feet and inches — this tool bridges all three. Pick your project type (lawn area or raised bed), add an order-over allowance for settling, and get cubic yards plus exact bag equivalents. No sign-up, no tracking: the math runs entirely in your browser.
By HowMuchBuild Editorial TeamCalculation reviewedUpdated October 2026
ft
in
ft
in
inches — 3–4″ is a common rule of thumb for topdressing
Bulk topsoil typically settles ~20–30% as it compacts — ordering a little over is cheap insurance.
Estimated cost
What will it cost?
Enter your local store prices — prices vary by region.
Bulk topsoil
6.11 cu yd
—
Topsoil bags (1 cu ft)
165 bags
—
Topsoil bags (1.5 cu ft)
110 bags
—
Estimate — prices vary by store and region. Check your local store for current pricing.
You need
6.11cubic yards
Exact volume 5.56 cu yd (150 cu ft) · includes 10% order-over allowance
150
cu ft · exact volume
165
bags · 1 cu ft bags
110
bags · 1.5 cu ft bags
| Bag size | Bags needed | Bags per yard |
|---|---|---|
| 1 cu ft | 165 | 27 |
| 1.5 cu ft | 110 | 18 |
How we calculated it
- Volume = 20 ft × 30 ft × (3″ topsoil depth ÷ 12) = 150 cu ft
- = 150 cu ft ÷ 27 = 5.56 cu yd
- With 10% order-over allowance (for settling) = 165 cu ft = 6.11 cu yd
- 1 cu ft bags = 165 ÷ 1 = 165 → round up = 165 bags
- 1.5 cu ft bags = 165 ÷ 1.5 = 110 → round up = 110 bags
Estimates for planning. Bag equivalents are exact arithmetic (27 cu ft = 1 cu yd). Bulk topsoil typically settles ~20–30% — the order-over allowance covers that; confirm delivery sizing with your supplier.
Worked example: 4×8 ft raised bed, 12″ deep
The most common raised bed size, filled a full foot deep. Full arithmetic, step by step:
- Volume: 4 ft × 8 ft × (12 ÷ 12) ft = 32 cu ft
- In cubic yards: 32 ÷ 27 = 1.19 cu yd
- Order size: round up and allow for settling → order 1.5 cu yd of bulk topsoil
- Bagged instead: 32 one-cubic-foot bags, or 32 ÷ 1.5 = 21.33 → 22 bags of the 1.5 cu ft size
Worked example: 20×30 ft lawn, 3″ of topsoil
- Volume: 20 ft × 30 ft × (3 ÷ 12) ft = 150 cu ft
- In cubic yards: 150 ÷ 27 = 5.56 cu yd → order 6 cu yd
- Bagged instead: 150 one-cubic-foot bags, or 150 ÷ 1.5 = 100 of the 1.5 cu ft bags
Coverage chart: what one cubic yard covers
Square feet covered by 1 cubic yard (27 cu ft) at each depth — exact arithmetic (324 ÷ depth in inches):
| Depth | Area covered by 1 cu yd |
|---|---|
| 1″ | 324 sq ft |
| 2″ | 162 sq ft |
| 3″ | 108 sq ft |
| 4″ | 81 sq ft |
| 6″ | 54 sq ft |
| 12″ | 27 sq ft |
Topsoil for common raised beds
Exact volumes — add 10–30% for settling when ordering bulk:
| Bed size | Volume | Cubic yards | 1 cu ft bags | 1.5 cu ft bags |
|---|---|---|---|---|
| 2×4 ft, 6″ deep | 4 cu ft | 0.15 | 4 | 3 |
| 4×4 ft, 6″ deep | 8 cu ft | 0.30 | 8 | 6 |
| 4×8 ft, 6″ deep | 16 cu ft | 0.59 | 16 | 11 |
| 4×8 ft, 12″ deep | 32 cu ft | 1.19 | 32 | 22 |
| 4×12 ft, 12″ deep | 48 cu ft | 1.78 | 48 | 32 |
The formulas
Volume (both modes)
V = Length × Width × Depth — all in feet, depth converted from inches (÷ 12).
Cubic yards
cu yd = V ÷ 27 — exact, since one cubic yard is exactly 27 cubic feet. With an order-over allowance: V × 1.10 ÷ 27 (adjust the slider for 0–30%).
Bag equivalents
Bags = ⌈ V ÷ bag size ⌉ — 27 bags of 1 cu ft, or 18 bags of 1.5 cu ft, per cubic yard. Always round up; partial bags don't exist at the register.
Frequently asked questions
How many cubic feet are in a cubic yard?
27. A yard is 3 feet, so 3 × 3 × 3 = 27 cubic feet — exact, no rounding involved.
How many bags of topsoil make a cubic yard?
27 bags of the 1 cu ft size, or 18 bags of the 1.5 cu ft size (27 ÷ 1.5 = 18). That's exact arithmetic from the 27 cu ft per yard.
How much topsoil do I need for a 4×8 raised bed?
A 4×8 ft bed filled 12 inches deep is 4 × 8 × 1 = 32 cu ft, which is 32 ÷ 27 = 1.19 cubic yards. Order about 1.5 yards of bulk topsoil to cover settling, or 32 one-cubic-foot bags (22 of the 1.5 cu ft bags).
Why should I order extra topsoil?
Bulk topsoil typically settles 20–30% as it compacts and organic matter breaks down (typical guidance), and no grade is perfectly even. A 10–30% order-over allowance is cheap insurance — running short mid-project means a second delivery fee.
How deep should topsoil be for a new lawn?
As a rule of thumb (guidance): 3–4 inches of quality topsoil is common for topdressing or renovation, and 4–6 inches of workable soil for a brand-new lawn bed. Deeper than that, blend with what's underneath rather than stacking pure topsoil.
Is it cheaper to buy topsoil in bulk or in bags?
Bags win for small jobs; bulk wins once you're near a cubic yard or more (guidance). A bagged cubic yard costs far more per yard than bulk delivered — but a bulk delivery has a minimum and a delivery fee, so small beds are cheaper in bags.
Can I fill a raised bed with topsoil alone?
You can, but it's not ideal (guidance). Straight topsoil compacts over a season and drains slowly. A common approach is roughly 60% topsoil blended with 40% compost and aeration material — better drainage, better roots.
Settling and the order-over allowance
Freshly delivered bulk topsoil is loose; once spread, rained on, and walked on, it typically settles about 20–30% (typical guidance). That's why the calculator includes an order-over slider — defaulting to 10%, adjustable to 30%. For raised beds, slightly overfilling is self-correcting: the bed sinks to level within a few weeks. For lawns, the allowance covers low spots and uneven subgrade. Bagged soil needs no such allowance — you buy the exact cubic footage, which is one reason bags are simpler for small beds.
Keep estimating