Ordering bulk landscape material (topsoil, gravel, bark, sand, compost, decorative rock) is priced and delivered by the cubic yard. Get the math right and the truck arrives with exactly what you need. Get it wrong and you either run short halfway through the project or pay for material you can't use.
How to calculate cubic yards (the formula)
Length (ft) × Width (ft) × Depth (inches) ÷ 324 = Cubic Yards
Same formula works for any bulk material: topsoil, gravel, bark, sand, compost, decorative rock. Only the recommended depth changes by material.
Worked example. A 20-ft × 8-ft garden bed at 4 inches deep: 20 × 8 × 4 ÷ 324 = 1.98 cubic yards (round up to 2 yards).
Where does 324 come from? 1 cubic yard = 27 cu ft. Since depth is in inches and length/width in feet, the conversion factor is 27 × 12 = 324. Prefer measuring depth in feet? Divide by 27 instead; same answer.
Free Cubic Yard Calculator
Enter your dimensions and pick a material. Results update instantly, with real Harbor Soils pricing.
Estimates use pickup prices at our Gig Harbor yard; delivery adds a flat fee. Weights are typical values and vary with moisture.
Below the calculator you'll find the simple formula behind it, lookup tables for the most common project sizes, and the weight-per-yard numbers that determine whether you need delivery or can pick up.
Planning a multi-area or multi-layer project?
Our full Landscape Material Calculator picks the right product depth for you and handles multiple areas and layers in one estimate, with a summary you can email or call in.
What is a cubic yard?
A cubic yard is a volume measurement: 3 feet wide by 3 feet long by 3 feet tall. That's 27 cubic feet, or a cube about waist-high on a tall adult. Bulk landscape suppliers (us included) sell by the cubic yard, almost always called just "a yard."
The cubic yard formula
Length (ft) × Width (ft) × Depth (inches) ÷ 324 = Cubic Yards
This one formula covers topsoil, gravel, bark, sand, compost: anything sold by volume. The 324 is just a unit conversion: it's 27 (cubic feet per yard) × 12 (inches per foot) ÷ 1, which lets you keep depth in inches where most people naturally measure it.
Worked example. A garden bed 20 feet long, 8 feet wide, with 4 inches of 3-Way Topsoil:
20 × 8 × 4 ÷ 324 = 1.98 cubic yards; order 2 yards.
If you'd rather measure depth in feet, divide by 27 instead: L × W × D(ft) ÷ 27. Same answer.
Inches to feet conversions
- 2 inches = 0.17 feet
- 3 inches = 0.25 feet
- 4 inches = 0.33 feet
- 6 inches = 0.50 feet
- 12 inches = 1.00 feet
Topsoil quick-reference (4″, 6″, 12″ deep)
Most lawn top-dressing runs 1–2 inches. New lawn install or shallow garden beds, 4 inches. Deep garden beds and raised beds, 6–12 inches. Pricing assumes our 3-Way Topsoil Mix at $32.99/yard.
| Area (sq ft) | 4″ deep | 6″ deep | 12″ deep |
|---|---|---|---|
| 100 sq ft | 1.2 yds | 1.9 yds | 3.7 yds |
| 250 sq ft | 3.1 yds | 4.6 yds | 9.3 yds |
| 500 sq ft | 6.2 yds | 9.3 yds | 18.5 yds |
| 1,000 sq ft | 12.3 yds | 18.5 yds | 37 yds |
| 2,000 sq ft | 24.7 yds | 37 yds | 74 yds |
Bark and mulch quick-reference (2″, 3″, 4″ deep)
2 inches refreshes existing beds. 3 inches is the standard for weed suppression and is what we recommend for most projects. 4 inches is appropriate for paths and high-traffic zones. Pricing assumes our Fine Bark at $35.99/yard or Medium Bark at $36.99/yard.
| Area (sq ft) | 2″ deep | 3″ deep | 4″ deep |
|---|---|---|---|
| 100 sq ft | 0.6 yds | 0.9 yds | 1.2 yds |
| 250 sq ft | 1.5 yds | 2.3 yds | 3.1 yds |
| 500 sq ft | 3.1 yds | 4.6 yds | 6.2 yds |
| 1,000 sq ft | 6.2 yds | 9.3 yds | 12.3 yds |
| 2,000 sq ft | 12.4 yds | 18.5 yds | 24.7 yds |
Gravel and crushed rock quick-reference (3″, 4″, 6″ deep)
3 inches works for thin walking paths over a compacted base. 4 inches is the standard finish layer for a residential driveway. 6 inches is what you'd want for a new driveway build (3" base + 3" top) or a heavy-load surface. Pricing assumes 5/8 Minus or 3/4 Minus Harbor Blue; both are common driveway grades. See our 5/8 minus guide and how to install a gravel driveway for which to pick.
| Area (sq ft) | 3″ deep | 4″ deep | 6″ deep |
|---|---|---|---|
| 100 sq ft | 0.9 yds | 1.2 yds | 1.9 yds |
| 250 sq ft | 2.3 yds | 3.1 yds | 4.6 yds |
| 500 sq ft | 4.6 yds | 6.2 yds | 9.3 yds |
| 1,000 sq ft | 9.3 yds | 12.3 yds | 18.5 yds |
| 2,000 sq ft | 18.5 yds | 24.7 yds | 37 yds |
Circular beds (by diameter)
For round planting beds, fire-pit circles, or tree wells, use diameter. Volume is π × r² × depth.
| Diameter | 2″ deep | 3″ deep | 4″ deep | 6″ deep |
|---|---|---|---|---|
| 4 ft | 0.08 yd | 0.12 yd | 0.16 yd | 0.25 yd |
| 6 ft | 0.18 yd | 0.27 yd | 0.36 yd | 0.55 yd |
| 8 ft | 0.32 yd | 0.48 yd | 0.64 yd | 0.96 yd |
| 10 ft | 0.50 yd | 0.75 yd | 1.0 yd | 1.5 yds |
| 15 ft | 1.1 yds | 1.7 yds | 2.2 yds | 3.4 yds |
How much does a cubic yard weigh?
Weight matters because it determines whether your truck can legally haul the load. A half-ton pickup (F-150, Silverado 1500, Tundra) has a payload rating right around 1,500–2,000 lbs. One yard of moist topsoil or any crushed rock is already at or over that limit.
| Material | Weight per cubic yard | Haul notes |
|---|---|---|
| Topsoil (moist) | 2,000–2,500 lbs | 1 yd is at or over half-ton payload |
| Compost | 1,000–1,300 lbs | Half-ton handles 1 yd comfortably |
| Bark / mulch (dry) | 400–800 lbs | Lightest common material; easy to haul |
| Sand | 2,500–2,700 lbs | Delivery recommended for 1+ yd |
| Crushed gravel | 2,700–3,000 lbs | Heaviest common material; delivery |
| Decorative rock | 2,500–3,500 lbs | Always delivery |
Cubic yards to tons and bags
Cubic yards to tons
- Topsoil: 1 yd³ ≈ 1.1–1.25 tons
- Crushed gravel: 1 yd³ ≈ 1.4–1.5 tons
- Sand: 1 yd³ ≈ 1.3–1.4 tons
- Bark / mulch: 1 yd³ ≈ 0.2–0.4 tons
Cubic yards to bags
- 1 cubic yard = 13.5 bags of 2-cubic-foot material
- 1 cubic yard = 9 bags of 3-cubic-foot material
Bulk delivery becomes cheaper than bags somewhere between 1 and 2 yards depending on material. 3-Way Topsoil at $32.99/yard works out to roughly $2.45 per 2-cu-ft bag equivalent, about a third of big-box bagged-topsoil pricing.
Real project calculations
Garden bed top-dress (2″ compost)
400 sq ft garden, 2 inches of Mushroom Compost:
400 × 2 ÷ 324 = 2.47 yards → order 3 yards. At $74.99/yd: $224.97.
Four 4×8 raised beds (12″ deep)
Filling with our Garden Mix:
4 beds × 32 sq ft × 12 ÷ 324 = 4.74 yards → order 5 yards. At $61.99/yd: $309.95.
40-ft gravel walking path (3″ deep)
3 ft wide × 40 ft long, finished in 5/8 Minus:
3 × 40 × 3 ÷ 324 = 1.11 yards → order 1.5 yards (paths compact 15–20%). At $34.99/yd: $52.49.
12×60-ft gravel driveway (4″ base + 2″ top)
Common new-driveway build, with 3/4 minus base and 5/8 minus topcoat:
Base: 12 × 60 × 4 ÷ 324 = 8.9 yards
Top: 12 × 60 × 2 ÷ 324 = 4.4 yards
Total: ~13.3 yards. Order 14–15 yards to allow for compaction.
Full breakdown in our gravel driveway installation guide.
Always round up: here's why
Order 5–10% more than the calculator says:
- Irregular ground. Real beds have low spots that need extra material to level.
- Compaction. Crushed rock loses 15–20% of its loose volume after compaction. Topsoil and bark settle ~10% in the first season.
- Your measurements are estimates. You're not running a survey crew. Tape-measure accuracy is rarely better than a few percent.
- A second delivery costs money. Extra yardage can be stockpiled and used for top-up later. A short order means a return trip charge.
Skip the math: let us run the numbers
Our Landscape Material Calculator picks the right product depths for you (3" for mulch, 4" for driveway top, etc.), handles multi-area and multi-layer projects, and gives a quantity in yards plus a copy-to-clipboard summary you can email or call in.
Or call us at 253-857-5125 with your project dimensions and we'll quote yardage and delivery before you order. We deliver topsoil, gravel, bark, compost, sand, and decorative rock throughout Gig Harbor, Port Orchard, Purdy, Artondale, Fox Island, Bremerton, Silverdale, Poulsbo, Bainbridge, and the rest of Kitsap and Pierce Counties.
Browse delivery by material: Topsoil · Crushed Rock · Sand & Gravel · Bark & Mulch · Compost · Decorative Rock · Rockery
Frequently asked questions
How do you calculate cubic yards?
Multiply length (feet) by width (feet) by depth (inches), then divide by 324. For a 20-ft × 8-ft garden bed at 4 inches deep: 20 × 8 × 4 ÷ 324 = 1.98 cubic yards (round up to 2). If you prefer to measure depth in feet, divide by 27 instead of 324; same answer either way.
How do I calculate cubic yards of dirt, soil, gravel or mulch?
Same formula for any bulk landscape material: length (ft) × width (ft) × depth (inches) ÷ 324 = cubic yards. The math doesn't change between dirt, topsoil, gravel, sand, bark or compost; only the recommended depth changes. Driveways need 4–6 inches of gravel, garden top-dress wants 2–4 inches of topsoil or compost, mulch beds run 2–3 inches.
How many cubic feet are in a cubic yard?
27 cubic feet equals 1 cubic yard. A cubic yard is a cube 3 ft × 3 ft × 3 ft.
How many bags of topsoil equal one cubic yard?
13.5 bags of 2-cubic-foot material, or 9 bags of 3-cubic-foot material. Bagged topsoil typically runs $5 to $8 per bag, so a yard's worth in bags costs $90 to $120, compared to $32.99/yard for our 3-Way Topsoil in bulk. Bulk wins on cost for any project over about 1.5 yards.
Will one cubic yard of topsoil fit in my pickup truck?
A half-ton pickup (F-150, Silverado 1500, Tundra) is at or slightly over its payload rating with one yard of moist topsoil (2,200 to 2,500 lbs). For two yards or any heavier material like crushed rock, you need a 3/4-ton truck or delivery. Going over payload damages suspension, tires, and brakes.
How do I calculate cubic yards for an irregular-shaped area?
Break it into rectangles and circles you can measure, calculate each, then add them up. An L-shaped bed is two rectangles. A curved bed can be approximated as a rectangle plus a half-circle. When in doubt, sketch it on graph paper and count the squares; each square at 1 ft = 1 sq ft.
How much extra should I order for compaction and settling?
Add 10 to 15 percent for most projects. Topsoil and bark settle ~10 percent in the first season. Crushed rock loses 15 to 20 percent of its loose volume after compaction. Order a small surplus rather than coming up short on delivery day.
How do I calculate for slopes or varied depth?
Use the average depth. Measure the shallowest and deepest points, average them, then plug that number into the formula. A bed that ranges from 2 inches deep at one end to 4 inches at the other averages to 3 inches.
At what volume is bulk delivery cheaper than bagged?
About 1.5 cubic yards. Below that, bagged from a big-box store is competitive once you factor in delivery fees. Above 2 yards, bulk is dramatically cheaper. Most landscape projects past a single garden bed cross that threshold.
Why does another calculator give a different total?
Most calculators use the same math (L × W × D ÷ 324 or ÷ 27). Differences come from rounding, whether the calculator adds a settling buffer automatically, and depth assumptions. If two calculators agree within 10 percent, both are fine. If one is wildly different, double-check its formula.
What if I order too much?
Keep it. Topsoil and bark stockpile well under a tarp and you'll use it for top-up next year. Compost holds best in a covered pile. Gravel can sit indefinitely.
What if I order too little?
Call us at 253-857-5125. Small follow-up loads are often possible the same week, sometimes the same day, depending on the route.