# How many cubic feet is it?

Computes the volume of a box or a cylinder, times how many, in cubic feet, with the same volume in cubic inches, cubic yards, cubic metres, US gallons and litres.

- Page: https://www.acalculator.org/construction/cubic-feet-calculator
- JSON spec: https://www.acalculator.org/construction/cubic-feet-calculator.json
- Version: 27cc4601f23a

## Default answer

Example with the default inputs (Shape Box, Length 4 ft, Width 3 ft, Height 2 ft, How many 1): The volume is 24 ft³.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| shape | Shape | A box (rectangular prism), or a cylinder. |
| len | Length | The length of the box. |
| wid | Width | The width of the box. |
| dia | Diameter | The diameter of the cylinder. |
| h | Height | The height of the box or cylinder. |
| qty | How many | How many of these shapes. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| cubicFeet | Volume | The total volume in cubic feet. |
| cubicInches | Cubic inches | The total volume in cubic inches (1,728 in a cubic foot). |
| cubicYards | Cubic yards | The total volume in cubic yards (27 cubic feet each). |
| cubicMeters | Cubic metres | The total volume in cubic metres. |
| gallons | US gallons | The total volume in US gallons (231 cubic inches each). |
| liters | Litres | The total volume in litres. |

## Method

box: length × width × height; cylinder: π × diameter² ÷ 4 × height; × how many

## Assumptions

- Each size may be in any length unit, including feet and inches together; the volume uses 1 ft = 12 in = 0.3048 m exactly.
- Gallons are US liquid gallons of 231 cubic inches.

## Worked examples

1. shape = box, len = 1.2192, wid = 0.9144, h = 0.6096, qty = 1 gives cubicFeet = 0.679604. Source: hand calculation in content.mdx: 4 × 3 × 2 = 24 ft³ = 179.5 US gal.
2. shape = box, len = 0.4572, wid = 0.3048, h = 0.254, qty = 5 gives cubicFeet = 0.17698. Source: hand calculation in content.mdx: 18 × 12 × 10 = 2,160 in³ = 1.25 ft³; × 5 = 6.25 ft³.
3. shape = cylinder, dia = 0.6096, h = 0.9144, qty = 1 gives cubicFeet = 0.26688. Source: hand calculation in content.mdx: π × 2² ÷ 4 × 3 = 3π = 9.425 ft³.

## FAQ

### How do I calculate cubic feet?

Multiply length × width × height, all in feet. A box 4 ft × 3 ft × 2 ft is 4 × 3 × 2 = 24 cubic feet.

### How do I calculate cubic feet from inches?

Multiply the three sizes in inches and divide by 1,728, the number of cubic inches in a cubic foot (12 × 12 × 12). A box 18 × 12 × 10 in is 2,160 in³ ÷ 1,728 = 1.25 ft³.

### How many gallons are in a cubic foot?

A US gallon is 231 cubic inches, so a cubic foot (1,728 in³) holds 1,728 ÷ 231 = 7.48 US gallons, or 28.32 litres.

### How do I find the cubic feet of a cylinder?

Multiply π × diameter² ÷ 4 by the height. A drum 2 ft across and 3 ft tall is π × 4 ÷ 4 × 3 = 9.42 ft³.

### How many cubic feet are in a cubic yard?

A yard is 3 feet, so a cubic yard is 3 × 3 × 3 = 27 cubic feet. Divide cubic feet by 27 to get cubic yards.

### Can I mix feet and inches?

Yes. Type a size such as 4 ft 6 in, or pick ft + in in the unit list. Each size is converted before the multiplication.

## Sources

- NIST SP 811 (2008), Appendix B: 1 ft = 12 in = 0.3048 m exactly; 1 US gallon = 231 in³ = 3.785411784 L exactly.