ConcreteCalc

Concrete Volume Calculator

Need the raw concrete volume in cubic feet, cubic yards, or cubic meters? Enter length, width, and thickness and this calculator returns all three units at once, with a waste factor. This is the unit-conversion and formula page: for a per-bag breakdown use the bag calculator, and when you are ready to place a ready-mix order the yard calculator covers quarter-yard rounding and minimum loads.

ft
ft
in
%
Pin itSLAB · ft/inLength (ft)Width (ft)T (in)

Total volume required

2.04Cubic Yards

Cubic feet

55.00

Cubic meters

1.56

Bags (80 lb)

92

Bags by size

40 lb

184

50 lb

147

60 lb

123

80 lb

92

Estimate includes your waste factor. Figures are estimates, not a quote.

How to use this calculator

  1. 1Enter length and width in feet and thickness in inches (switch to metric for meters and centimetres).
  2. 2Set Quantity if you are adding up several identical pours into one volume.
  3. 3Add a waste factor so the converted volume already includes a planning margin.
  4. 4Read the volume in cubic feet, cubic yards, and cubic meters together — pick the unit your supplier uses.

Formula & rounding

Volume = length × width × thickness, all in feet (thickness in inches ÷ 12). Convert with fixed factors: cubic feet ÷ 27 = cubic yards; cubic feet × 0.0283168 = cubic meters; cubic yards × 0.7646 = cubic meters. Volume figures are shown to two decimals; only bag counts round up.

Convert a 10 ft × 10 ft × 6 in pour to yards and meters

  • Volume = 10 × 10 × (6 ÷ 12) = 50 cubic feet
  • With 10% waste: 50 × 1.10 = 55 cubic feet
  • Cubic yards = 55 ÷ 27 = 2.04 cubic yards
  • Cubic meters = 55 × 0.0283168 = 1.56 cubic meters

= 55 cu ft ≈ 2.04 cubic yards ≈ 1.56 cubic meters

Metric input: a 3 m × 4 m × 0.1 m slab

  • Volume = 3 × 4 × 0.1 = 1.2 cubic meters
  • Cubic feet = 1.2 × 35.3147 = 42.4 cubic feet
  • Cubic yards = 42.4 ÷ 27 = 1.57 cubic yards
  • Switch the calculator to metric to enter meters and centimetres directly.

= 1.2 m³ ≈ 42.4 cu ft ≈ 1.57 cubic yards

Concrete volume unit conversions

The conversions are exact ratios, not estimates — they never change. Use them to move between the units a calculator, bag label, or ready-mix supplier expects.

FromToMultiply by
Cubic feetCubic yards÷ 27
Cubic feetCubic meters× 0.0283168
Cubic yardsCubic meters× 0.7646
Cubic metersCubic yards× 1.30795

A cubic yard is 3 ft × 3 ft × 3 ft = 27 cubic feet. Conversions are mathematical constants.

Frequently asked questions

How do I calculate concrete volume?

Multiply length × width × thickness with every dimension in the same unit. In feet, a 10 ft × 10 ft × 0.5 ft pour is 50 cubic feet. The calculator handles the inch-to-foot conversion for thickness and adds a waste factor.

How many cubic feet are in a cubic yard of concrete?

Exactly 27. A cubic yard is 3 feet on each side, and 3 × 3 × 3 = 27 cubic feet. To go from cubic feet to cubic yards, divide by 27; to go back, multiply by 27.

How do I convert cubic yards to cubic meters?

Multiply cubic yards by 0.7646. For example, 2 cubic yards × 0.7646 ≈ 1.53 cubic meters. To convert cubic feet to cubic meters instead, multiply by 0.0283168.

Should I use this page or the yard calculator to order ready-mix?

Use this page to get the pure volume and convert between units. Use the yard calculator when you are placing the order — it focuses on quarter-yard rounding, minimum loads, and short-load fees that affect what you actually buy.

What are the most common concrete volume mistakes?

The frequent ones are forgetting to convert thickness from inches to feet (a 6-inch slab is 0.5 ft, not 6), mixing units in one calculation, using the plan depth instead of the real formed depth, and skipping the waste factor. Measure the actual depth in several places and convert every dimension to the same unit before multiplying.

Should I calculate concrete volume in feet or meters?

Either works as long as every dimension uses the same system. In the US, suppliers sell ready-mix by the cubic yard, so imperial input is usually easiest; elsewhere concrete is ordered in cubic meters. This calculator shows all three units at once, so you can enter whichever you measured in and read the unit your supplier wants.

When should I use the volume calculator instead of the slab calculator?

Use this volume calculator when you just need the cubic-feet/yards/meters figure and the conversion math for any rectangular pour. Use the slab calculator when you want flatwork-specific defaults, thickness guidance, and a thickened-edge example. Both share the same volume engine; the difference is the context around it.

Assumptions & sources

Volume formula
length × width × thickness (all in feet); thickness in inches ÷ 12.
Unit conversions
cu ft ÷ 27 = cu yd; cu ft × 0.0283168 = m³; cu yd × 0.7646 = m³. Exact ratios.
Bag yields
≈0.60 cu ft per 80 lb bag (0.45 / 0.375 / 0.30 for 60 / 50 / 40 lb); rounded up.
Waste factor
Default 10%; the converted volumes include this margin once it is applied.
Scope
Volume and unit conversion only — ready-mix ordering rules and price are handled on the yard and cost pages.

See the methodology & sources for how these values, formulas, and rounding are chosen.

Helpful concrete guides

This is an estimate, not a quote. Concrete quantities, bag yields, block coverage, and prices vary with product, brand, mix, region, supplier, tax, delivery, and on-site conditions. Always confirm with your supplier and round up for safety. For structural or code-related work, consult a qualified professional or your local building authority.