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Cubic Feet Calculator.

Calculate cubic feet, cubic yards, and cubic meters for shipping, construction, and storage.

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How to Use

Enter length, width, and height to compute volume in cubic feet, cubic yards, and cubic meters — plus a quick estimate of concrete bags needed.

FAQs

How do I calculate cubic feet?

Cubic feet = Length × Width × Height (all in feet). You can enter other units (inches, meters, cm) and the calculator will convert for you.

How many cubic feet in a cubic yard?

1 cubic yard = 27 cubic feet. The calculator shows both values automatically.

How many 80lb bags of concrete fill 1 cubic foot?

An 80lb bag of concrete mix yields about 0.6 cubic feet when cured. The calculator rounds bag estimates up to whole bags.

How to Use the Cubic Feet Calculator

Calculate the volume of any rectangular prism in cubic feet, yards, and meters.

  1. Choose a unit (feet, inches, meters, or centimeters).
  2. Enter the length, width, and height of the space.
  3. Read the volume in cubic feet, cubic yards, and cubic meters.
  4. Use the concrete bag estimates to plan material purchases.

Volume Formulas

Cubic Feet

ft³ = L(ft) × W(ft) × H(ft)

Volume is the product of length, width, and height in feet.

Example:

Input: 4 ft × 3 ft × 2 ft

Calculation: 4 × 3 × 2

Result: 24 ft³

Cubic Yards

yd³ = ft³ ÷ 27

1 cubic yard equals 27 cubic feet.

Example:

Input: 54 ft³

Calculation: 54 ÷ 27

Result: 2 yd³

Real-World Use Cases

Shipping Volume

Determine a package's volume for freight pricing.

Concrete

Estimate how many 80 lb bags of concrete to buy.

Tips

Tips

  • Convert all dimensions to feet before multiplying.
  • An 80 lb bag of concrete yields about 0.6 ft³ — round your bag count up to whole bags.

Cite this calculator

Canonical URL: https://mathify.one/en/construction/cubic-feet

Cite as: Mathify. (2026). Cubic Feet Calculator. https://mathify.one/en/construction/cubic-feet

Use Cases

Home Improvement Projects

Determine the volume of concrete needed for a slab, footing, or patio. Enter the dimensions in feet or inches to get cubic yards and bag count.

Example: A 10 ft × 10 ft slab, 4 inches thick, yields about 1.23 yd³.

Shipping and Storage

Calculate the cubic feet of a box or container to estimate shipping costs or storage space. Use any unit for length, width, and height.

Example: A box 2 ft × 3 ft × 4 ft = 24 ft³.

Frequently Asked Questions

How do I calculate cubic feet?
Enter the length, width, and height in any supported unit (feet, inches, meters, centimeters). The calculator converts all to feet and multiplies them to get cubic feet. For example, 2 ft × 3 ft × 4 ft = 24 ft³.
Can I mix units like feet and inches?
Yes, the calculator supports feet, inches, meters, and centimeters. You can enter each dimension in a different unit, and it will convert everything to feet before calculating the volume.
How many concrete bags do I need?
After calculating the volume in cubic feet, the calculator estimates the number of concrete bags based on standard bag sizes (e.g., 40, 60, or 80 lb bags). It uses typical coverage per bag, so you can plan your purchase.

Tips & Common Mistakes

Tips

  • Always measure the actual dimensions, not estimates, for accurate volume.
  • When mixing units, double-check that you've selected the correct unit for each dimension.
  • For concrete, add 5-10% extra to account for waste or spillage.
  • Use the cubic yard result for ordering bulk concrete, as it's the standard unit for ready-mix.

Common Mistakes to Avoid

  • Forgetting to convert all dimensions to the same unit before calculating.
  • Using the wrong bag size when estimating concrete bags—check the coverage on the bag.
  • Not accounting for the thickness of a slab when measuring height (e.g., using inches for height but feet for length).

Last updated: August 13, 2026