Cubic Yards Calculator
This free cubic yards calculator turns dimensions into the volume every bulk-material order needs. Slabs, footings, gravel beds, soil, and mulch are all priced by the cubic yard — and the most-missed conversion in remodeling is that one cubic yard is 27 cubic feet, not 3 or 9. Get it right and your concrete, gravel, and fill orders all land; get it wrong and you under-order by 3×.
Add multiple sections — a patio slab plus a footing, beds at different depths, a round Sonotube pour — each with its own depth in inches or feet, and subtract block-outs and voids for a net total. The calculator converts to cubic yards, cubic feet, and cubic meters, gives you the 80/60/40-lb concrete bag counts (45 × 80-lb bags make a yard), and tells you when ready-mix or bulk delivery beats bagging.
Built on solid geometry and the cubic-yard definition — no signup, no pricing. This is geometric (loose) volume; for a compacted gravel base, hand your number to the Gravel calculator, which adds the loose-to-compacted factor. When you have your volume, feed it into the Concrete, Gravel, Mulch, Sand, or Landscape Material calculator.
Cubic Yards Calculator
Turn length × width × depth — or round footings and triangular areas — into cubic yards, cubic feet, and cubic meters. Add multiple pours or beds at different depths, subtract voids, and get the concrete bag count or ready-mix order. The volume helper for every bulk-material calculator on the site.
Measurement unit
Volumes to measure
Waste / overage (optional)
Calculation Formulas
The base case for slabs, footings, beds, and fills. Keep every dimension in the same unit, then convert to cubic yards. Depth is usually the odd one out — a 4-inch slab is 0.333 ft thick.
Example:
A 20 ft × 10 ft slab at 4 in (0.333 ft) = 66.7 ft³ = 2.47 cu yd.
A cubic yard is a 3 ft × 3 ft × 3 ft box = 27 cubic feet. This is the single most-missed conversion — people divide by 3 or 9 instead of 27 and under-order by 3×.
Example:
66.7 ft³ ÷ 27 = 2.47 cu yd.
For round footings, columns, and Sonotube pours. Enter the tube diameter; the radius is half of it. Depth is the footing height.
Example:
A 12 in (1 ft) diameter footing 4 ft deep = π × 0.5² × 4 = 3.14 ft³ = 0.12 cu yd each.
For a circular fill with a hole in the middle — a tree ring, a fountain surround, a pipe trench around a tank. R is the outer radius, r the inner radius.
Example:
A 12 ft outer / 6 ft inner ring at 3 in deep = π × (6² − 3²) × 0.25 = 21.2 ft³ = 0.79 cu yd.
For triangular beds, corner fills, and wedge-shaped pours. Height is the perpendicular distance from the base, not a sloped side.
Example:
A 12 ft × 8 ft triangular bed at 3 in = ½ × 12 × 8 × 0.25 = 12 ft³ = 0.44 cu yd.
Subtract block-outs, drain pits, and embedded forms so you do not over-order concrete or fill. Each void is a volume removed from the total.
Example:
A 3 cu yd slab minus a 0.4 cu yd plumbing block-out = 2.6 cu yd of concrete.
Dry concrete mix is sold by weight but yields a known volume: an 80-lb bag makes about 0.60 ft³, a 60-lb bag 0.45 ft³, a 40-lb bag 0.30 ft³. That is 45 × 80-lb bags per cubic yard.
Example:
2.47 cu yd = 66.7 ft³ → ⌈66.7 ÷ 0.60⌉ = 112 × 80-lb bags (before waste).
Real pours and fills need extra for over-excavation, uneven subgrade, spillage, and supplier rounding. 5–10% is typical for concrete slabs; 10%+ for gravel and soil over rough ground.
Example:
2.47 cu yd at 10% waste = 2.72 cu yd to order.
For metric plans and imported equipment specs. One cubic yard is about 0.765 cubic meters.
Example:
2.72 cu yd = 73.4 ft³ ÷ 35.315 = 2.08 m³.
Standard Constants
| Constant | Value | Description |
|---|---|---|
| 1 cubic yard | 27 cubic feet | A 3 ft × 3 ft × 3 ft box; the order unit for ready-mix concrete and bulk material. |
| 1 cubic yard | 0.7646 m³ | Metric equivalent for plans and imported specs. |
| 80 lb concrete bag | ≈ 0.60 ft³ | Mixed yield per Quikrete TDS; 45 bags make one cubic yard. |
| 60 lb concrete bag | ≈ 0.45 ft³ | Mixed yield; 60 bags make one cubic yard. |
| 40 lb concrete bag | ≈ 0.30 ft³ | Mixed yield; 90 bags make one cubic yard. |
| Retail soil/mulch bags | 0.5, 1.0, 2.0 ft³ | Standard bag sizes at Home Depot / Lowe’s for bagged landscape material. |
| Slab waste factor | 5–10% | Allowance for subgrade variation and spillage on a concrete pour. |
| Gravel/soil waste factor | 10–15% | Larger allowance over rough or sloped ground where material is lost to the subgrade. |
| π (pi) | 3.14159 | Used for every round footing, column, and ring volume. |
Note: All calculations include appropriate waste factors based on project complexity and material type. Results are estimates and should be verified by professionals before purchasing materials.
ASTM C94 — Standard Specification for Ready-Mixed Concrete(ASTM C94/C94M)
View StandardGoverns how ready-mix concrete is batched, measured, and delivered — by the cubic yard.
Key Requirements:
- •Concrete is batched and sold by volume — the cubic yard (or cubic meter).
- •Delivered yield is verified by unit weight (ASTM C138); order net volume plus a waste allowance.
- •Short loads (under ~1 yd³) typically carry a per-load surcharge — bagging can be cheaper at that size.
ACI 318 — Building Code Requirements for Structural Concrete(ACI 318)
View StandardThe structural concrete code; governs footing and slab thickness, which drive the volume you order.
Key Requirements:
- •Minimum footing and slab thicknesses are set by code and loading — confirm depth before computing volume.
- •Reinforcement and cover requirements do not change concrete volume but affect form depth.
- •Use the design thickness, not a nominal one, when calculating cubic yards.
Concrete Bag Yields — Manufacturer TDS(Quikrete / Sakrete TDS)
View StandardPublished mixed-yield-per-bag figures used to convert volume into a bag count.
Key Requirements:
- •80 lb concrete mix yields about 0.60 ft³ mixed; 60 lb about 0.45 ft³; 40 lb about 0.30 ft³.
- •45 × 80-lb bags equal one cubic yard before waste.
- •High-early and crack-resistant mixes can yield slightly differently — check the bag.
IRC — Footing & Slab Provisions(IRC R403 / R506)
View StandardResidential code provisions for footing size and concrete slabs-on-ground that set the dimensions you measure.
Key Requirements:
- •Footing width and thickness are set by the IRC tables for soil bearing and load.
- •Slabs-on-ground have minimum thickness and base requirements.
- •Frost depth sets footing depth in cold climates — deeper footings mean more volume.
NIST Handbook 44 — Volume Unit Definitions(NIST HB 44)
View StandardThe authority for US customary volume units used in trade — the cubic yard and cubic foot.
Key Requirements:
- •1 cubic yard = 27 cubic feet, exactly.
- •1 cubic foot = 1,728 cubic inches.
- •Bulk material sold by the cubic yard is measured loose, not compacted.
Standards Disclaimer: Standards and codes are subject to periodic updates. Always verify current requirements with local building authorities and professional engineers before beginning construction. Links provided are for reference only.
Geometric Volume vs. Compacted Volume
Why gravel orders are bigger than the math
This tool computes the volume of the space you are filling. Compactable materials (crusher run, road base, RCA) shrink 10–25% when tamped, so you must order MORE loose material than the finished volume. For those, run the Gravel calculator, which adds the loose-to-compacted factor on top of this number.
Regional Examples:
Bagged vs. Ready-Mix Concrete Crossover
Where short-load fees flip the math
For small pours, bagged mix avoids ready-mix short-load surcharges; for larger pours, ready-mix wins on labor and consistency. The crossover is roughly 1 cubic yard, but local short-load fees and bag prices move it.
Regional Examples:
Frost Depth & Footing Volume
Cold climates pour deeper
Footings must extend below the local frost line. A deck or fence footing that is 12 inches deep in the South may need to be 42–48 inches deep in the North, multiplying the concrete volume per hole.
Regional Examples:
Delivery Minimums & Spoil Hauling
Bulk suppliers won’t deliver a wheelbarrow
Bulk gravel, soil, and concrete suppliers carry delivery minimums (often 1–5 yd³) and load fees. Excavation also produces spoil — the dirt you remove — which is bulked-up volume that has to go somewhere.
Regional Examples:
Loose vs. In-Place for Soil & Mulch
Bagged bed material settles
Bagged and bulk soil/mulch are measured loose. They settle after watering and foot traffic, so a freshly spread 3-inch bed thins over a season. Order to the spread (loose) depth you want at install.
Regional Examples:
Before You Build
- •Contact your local building department for specific requirements
- •Verify frost line depths, wind zones, and seismic requirements for your area
- •Check if permits are required and schedule required inspections
- •Consult with a local contractor familiar with local codes
Related Calculators
Concrete Calculator
Instantly calculate cubic yards, 60lb/80lb bags & cost for slabs, footings & posts. Free concrete calculator, results in seconds—no signup needed.
Gravel Calculator
Free gravel calculator with material-specific densities, compaction factor & waste overage. Get cubic yards, tons & bag count in seconds.
Mulch Calculator
Instantly calculate mulch in cubic yards & bags for any bed size. Compares bulk vs bagged cost. Free, accurate landscaping calculator—no signup.
How to Use This Calculator
- Pick the unit your plan dimensions are in — feet, inches, yards, meters, or centimeters.
- For each pour, bed, or fill, choose a shape (rectangle/slab, circle/cylinder, ring, or triangle) and enter its dimensions.
- Enter the depth or thickness for that section and choose inches or feet — a 4-inch slab and a 4-foot footing can sit in the same calculation.
- Use the quantity field for several identical items (e.g. 12 round footings), and add more sections with “Add volume” for multi-pour jobs.
- Use “Subtract void” for block-outs, drain pits, and embedded forms so concrete and fill come out net.
- Set a waste/overage factor — 5–10% is typical for slabs, 10%+ for gravel and soil over rough ground.
- Click Calculate to see cubic yards, cubic feet, cubic meters, the concrete bag counts, and whether to bag it or order ready-mix. Then open the Concrete, Gravel, or Mulch calculator to turn volume into materials.
Geometric Volume vs. Compacted Volume
This calculator returns the geometric volume of the space you are filling — the math of length × width × depth. That is exactly right for concrete, soil, and clean decorative stone. But compactable materials (crusher run, road base, recycled concrete) shrink 10–25% when they are tamped, so you must order MORE loose material than the finished volume. For those, take this number to the Gravel calculator, which applies the AASHTO/TxDOT loose-to-compacted factor on top. Likewise, for concrete the choice between bagged mix and ready-mix flips around one cubic yard: below it, 80-lb bags usually beat a ready-mix short-load fee; above it, ready-mix (sold by the yard under ASTM C94) wins on labor and consistency.
Frequently Asked Questions
How do I calculate cubic yards?
Multiply length × width × depth to get cubic feet, then divide by 27 to get cubic yards (a cubic yard is a 3 ft × 3 ft × 3 ft box = 27 cubic feet). The catch is units: depth is usually in inches, so convert it to feet first — a 4-inch slab is 0.333 ft thick. A 20 ft × 10 ft slab at 4 inches is 20 × 10 × 0.333 = 66.7 cubic feet ÷ 27 = 2.47 cubic yards. This calculator does the unit conversion for you, including round and triangular shapes.
How many cubic feet are in a cubic yard?
Exactly 27. A cubic yard is 3 feet on every side, and 3 × 3 × 3 = 27 cubic feet. This is the single most-missed conversion in material ordering — people divide cubic feet by 3 or by 9 (the square-foot-to-square-yard factor) instead of 27, and end up ordering one-third of what they need. To go from cubic feet to cubic yards, always divide by 27.
How many bags of concrete are in a cubic yard?
It depends on bag size: about 45 × 80-lb bags, 60 × 60-lb bags, or 90 × 40-lb bags make one cubic yard. That is because an 80-lb bag of concrete mix yields roughly 0.60 cubic feet mixed (27 ÷ 0.60 = 45), a 60-lb bag about 0.45 cubic feet, and a 40-lb bag about 0.30 cubic feet, per the manufacturer's data sheets. The calculator shows all three bag counts for your volume. Above about one cubic yard, ready-mix delivery usually beats mixing dozens of bags by hand.
Should I order more cubic yards than the calculator shows?
Yes — add a waste/overage factor, which this calculator includes. For concrete slabs, 5–10% covers subgrade variation and spillage. For gravel and soil spread over rough or sloped ground, 10–15% is safer because material is lost into the subgrade. Running short on a concrete pour is far worse than a little extra, because a cold joint from a second delivery can compromise the slab. The calculator shows both the raw geometric volume and the with-waste total.
Why is my gravel order bigger than the cubic yards here?
Because this calculator returns geometric (loose) volume — the actual size of the space you are filling. Compactable materials like crusher run, road base, and recycled concrete shrink 10–25% when tamped, so you have to order MORE loose material than the finished compacted volume. For those, take this number to the Gravel calculator, which adds the AASHTO/TxDOT loose-to-compacted factor on top. Clean decorative stone and concrete barely compact, so the geometric volume is what you order.
How do I figure cubic yards for round footings or columns?
Round pours use cylinder volume: V = π × (diameter ÷ 2)² × depth. For a 12-inch (1 ft) diameter footing 4 feet deep, that is π × 0.5² × 4 = 3.14 cubic feet, or 0.12 cubic yards each. Set the shape to Circle/cylinder, enter the tube (Sonotube) diameter — not the radius — and the footing depth, then use the quantity field for the number of piers. The calculator totals them and adds your waste factor.
Does this calculator include the price of concrete or gravel?
No. Like every calculator on the site, it is pricing-free — it gives you quantities (cubic yards, cubic feet, bag counts), not dollar figures, because material and delivery prices drift too fast to keep accurate. Cubic yards is the upstream measurement; take the volume to a local ready-mix or aggregate supplier for a current quote, or hand it to the Concrete, Gravel, Mulch, or Sand calculator to break it down into materials.