cubic yard calculator
Use this cubic yard calculator to turn real-world measurements into cubic yards (yd³) for common projects like concrete slabs, gravel driveways, mulch beds, topsoil, and landscaping fill.
Choose a shape, enter dimensions in feet, inches, or meters, and get a premium breakdown with conversions to cubic feet and cubic meters. For more tools, see All Calculators.
Calculate cubic yards from dimensions
Tip: thickness is often entered in inches (for example, a 4-inch slab). Precision affects display only; calculations run at full floating precision.
Results
Results appear only after valid input. Volume conversions are exact math; weight is an estimate when enabled (density varies by moisture, compaction, and supplier specs).
How it works
A cubic yard (yd³) is a unit of volume often used in construction and landscaping. The key conversion is: 1 yd³ = 27 ft³. This calculator converts your measurements into a consistent base unit (feet or meters), computes volume using the chosen shape formula, then converts into cubic yards for the final answer.
Variables used: L = length, W = width, D = depth/thickness, r = radius, h = height. Inches are converted to feet by dividing by 12. Meters are converted to feet using 1 m = 3.280839895 ft.
- Rectangular / Slab: cubicFeet = L(ft) × W(ft) × D(ft) → yd³ = cubicFeet ÷ 27
- Circular / Cylinder: radius = diameter ÷ 2 → cubicFeet = π × r² × h → yd³ = cubicFeet ÷ 27
- Area × Depth: cubicFeet = Area(ft²) × D(ft) → yd³ = cubicFeet ÷ 27 (or convert m² to ft² first)
Rounding policy: calculations run at full floating precision internally; the Precision selector changes display only (0–4 decimals). If you enable weight, results are shown as an estimate based on a typical density selection (or your custom density).
| Thickness | Feet equivalent | Where it shows up |
|---|---|---|
| 2 in | 0.1667 ft | Light topping, some paver bases |
| 4 in | 0.3333 ft | Typical residential slab thickness |
| 6 in | 0.5000 ft | Heavier pads and some driveways |
| 12 in | 1.0000 ft | Deep fill layers, raised beds |
Use cases
- Concrete slabs: Estimate cubic yards for patios, shed pads, walkways, and garage extensions.
- Mulch and bark: Convert bed dimensions into yd³ so you can compare bag coverage to bulk delivery.
- Gravel and crushed stone: Plan driveway top layers and base courses with a clear yd³ target.
- Topsoil and compost: Fill lawn low spots or garden expansions with a consistent volume estimate.
- Raised beds: Use Area × Depth to estimate soil volume when the bed shape is irregular but the footprint is known.
- Posts and footings: Use the cylinder mode for round holes, piers, and sonotube pours.
If your project involves engine geometry, you might also want a compression ratio calculator—different topic, same idea: accurate inputs produce reliable results.
Examples / Worked examples
Example 1: 12 ft × 10 ft slab, 4 in thick
- Convert thickness: 4 in ÷ 12 = 0.3333 ft
- Compute cubic feet: 12 × 10 × 0.3333 = 40.0 ft³
- Convert to cubic yards: 40.0 ÷ 27 = 1.4815 yd³
- With 2 decimals: 1.48 yd³
Example 2: Mulch bed 20 ft × 6 ft, 3 in deep
- Convert depth: 3 in ÷ 12 = 0.25 ft
- Cubic feet: 20 × 6 × 0.25 = 30.0 ft³
- Cubic yards: 30.0 ÷ 27 = 1.1111 yd³
- With 2 decimals: 1.11 yd³
Example 3: Round hole, 3 ft diameter, 12 in deep
- Convert depth: 12 in ÷ 12 = 1.0 ft
- Radius: diameter ÷ 2 = 3 ÷ 2 = 1.5 ft
- Cubic feet: π × 1.5² × 1.0 = 7.0686 ft³
- Cubic yards: 7.0686 ÷ 27 = 0.2618 yd³
- With 2 decimals: 0.26 yd³
After you calculate volume, remember that truck and bag quantities differ by product type. If you’re converting electrical units for site work, the Ohms Law Calculator can help with quick checks.
Common Mistakes
- Mixing inches and feet without converting thickness (for example, using “4” as feet instead of 4 inches).
- Forgetting that cubic yards are volume, not area—depth always matters.
- Using diameter as radius in cylinder calculations (radius is half the diameter).
- Rounding too early (rounding dimensions before calculating can compound error).
- Assuming weight is exact (density varies by moisture, compaction, and material grading).
Quick Tips
- Enter thickness in inches for slabs; it’s the most common way contractors specify depth.
- When ordering bulk material, consider adding 5–10% for waste/compaction as a general rule of thumb.
- Use the Area × Depth mode when the footprint is known but the shape isn’t perfectly rectangular.
- Use higher display precision if you’re near a threshold (like deciding between 1.0 vs 1.1 yd³).
- For weight estimates, use your supplier’s density if available and treat presets as rough guidance.
FAQ
How do I calculate cubic yards for a rectangular slab?
Measure the length and width of the slab, then measure thickness (depth). Convert everything to the same unit before multiplying. A reliable approach is to convert inches to feet by dividing by 12, calculate cubic feet as L(ft) × W(ft) × D(ft), then convert to cubic yards by dividing by 27. The calculator does these steps automatically and shows the substituted values so you can verify the math, which is especially helpful when thickness is provided in inches.
Why is 1 cubic yard equal to 27 cubic feet?
A yard is 3 feet, so a cubic yard is a cube that is 3 feet long, 3 feet wide, and 3 feet tall. Volume multiplies across all three dimensions: 3 × 3 × 3 = 27 cubic feet. This conversion is exact and is the backbone of most bulk material estimates in the U.S. and many contractor workflows. If you calculate volume in cubic feet first, dividing by 27 is the most direct way to reach cubic yards.
Should I enter thickness in inches or feet?
Either works as long as you choose the correct unit, but inches are common for slabs and surface layers. For example, 4 inches is typical for many residential slabs. Internally, the calculator converts inches to feet (in ÷ 12) so the volume formula stays consistent. If you’re working from metric plans, you can use meters as well; the calculator converts meters to feet (1 m = 3.280839895 ft) before computing cubic feet and cubic yards.
How do I calculate cubic yards for a round hole or cylinder?
For a cylinder, you need diameter and depth (height). Convert those to a consistent unit, then compute radius as diameter ÷ 2. The cylinder volume is π × r² × h. If you compute in feet, the result is cubic feet, which you then divide by 27 to get cubic yards. The calculator shows each step, including radius, the π portion, and the final conversion, so you can confirm you used diameter (not radius) in the input.
How accurate is the “tons” estimate for gravel, soil, or mulch?
It’s an estimate, not an exact conversion. Weight depends on density, and density varies with moisture content, compaction, particle size, and supplier grading. If you enable the estimate, you can choose a typical material preset or enter a custom density in lb/ft³, and the calculator will show the density used alongside the result. For the most accurate ordering, use your supplier’s published density and treat the preset ranges as a quick planning aid.
How many cubic yards do I need for a 10 ft × 10 ft area?
You need the depth. A 10 ft × 10 ft footprint is 100 ft². Multiply area by depth (in feet) to get cubic feet, then divide by 27 for cubic yards. For example, at 4 inches deep, depth is 0.3333 ft, so volume is 100 × 0.3333 = 33.33 ft³, and 33.33 ÷ 27 = 1.2346 yd³. If your depth changes, the result changes linearly, so depth is the key driver.
Why do my results change when I switch units?
They shouldn’t, as long as the numbers represent the same physical size. Switching units changes the scale of the input value. For example, 12 inches equals 1 foot, so “12 in” and “1 ft” should compute the same depth. If results differ, it usually means the numeric value was not converted when the unit changed (such as leaving “4” but switching from inches to feet). The calculator keeps your selected units visible next to each input to reduce this mistake.
Should I add extra cubic yards for waste or compaction?
Often, yes—especially for loose materials like mulch, soil, and gravel. A common planning approach is to add a small buffer, such as 5–10%, to account for uneven ground, settling, and spillage. Concrete planning may also include a buffer for forms, over-excavation, and finishing. The exact amount depends on your site conditions and material type, so treat it as a general rule of thumb and confirm with your contractor or supplier when accuracy is critical.
Related calculators
More Helpful Calculators
Quick site links
Accuracy, privacy, and sources
Accuracy & method
Runs locally in your browser; no data sent. Inputs are converted into consistent units, then standard geometry formulas are applied. Display rounding is optional and does not affect the underlying calculation precision.
Last Updated: January 21, 2026
Privacy-first: This widget does not transmit, store, or track your entries.
Sources & references
- 1 cubic yard (yd³) = 27 cubic feet (ft³)
- 1 meter (m) = 3.280839895 feet (ft)
- 1 cubic yard (yd³) ≈ 0.764554858 cubic meters (m³)
- Cylinder volume: V = π × r² × h
- Rectangular prism volume: V = L × W × D