Cubic Inches Calculator

What is a cubic inch?

A cubic inch (symbol: in³ or cu in) is a unit of volume in the United States customary and British imperial systems. It is the volume of a cube whose edges are each one inch (2.54 centimeters) long. Because it is a small unit, the cubic inch is well suited to compact, everyday measurements: engine displacement, the interior capacity of small boxes and containers, machine parts, and tooling specifications.

This calculator does two things at once. First, it computes the volume of a rectangular (box-shaped) space from its length, width, and height. Second, it lets you read that volume back in cubic inches or convert it to other common volume units such as cubic feet, cubic centimeters, liters, or gallons.

How does the calculator work?

For any rectangular box, the volume is simply the product of its three perpendicular dimensions. Enter the length, width, and height, and the calculator multiplies them together. Each dimension has its own unit selector, so you can mix inches, feet, yards, centimeters, meters, and millimeters — the tool converts everything to a common base before multiplying. The volume field also has a unit selector, so the same result can be displayed in cubic inches or instantly converted to another unit.

Formula

The volume $V$ of a rectangular space is:

$$V = l \times w \times h$$

where:

• $l$ is the length,
• $w$ is the width,
• $h$ is the height (or depth).

When all three dimensions are given in inches, the result is already in cubic inches. To convert that cubic-inch value to other units, multiply by the appropriate factor:

$$1\ \text{in}^3 = 16.3871\ \text{cm}^3 = 0.0163871\ \text{L} = 0.000578704\ \text{ft}^3$$

Because there are 12 inches in a foot, one cubic foot contains $12^3$ cubic inches:

$$1\ \text{ft}^3 = 12^3 = 1728\ \text{in}^3$$

Worked examples

Example 1: A small box in inches

A small box measures 2 in long, 3 in wide, and 4 in high. Its volume is:

$$V = 2 \times 3 \times 4 = 24\ \text{in}^3$$

So the box holds 24 cubic inches.

Example 2: A 10-inch cube

A cube ten inches on each side has a volume of:

$$V = 10 \times 10 \times 10 = 1000\ \text{in}^3$$

That is 1000 cubic inches, or about 16,387 cubic centimeters.

Example 3: A one-inch cube

A perfect cube one inch on each side has a volume of:

$$V = 1 \times 1 \times 1 = 1\ \text{in}^3$$

That single cubic inch equals about 16.3871 cubic centimeters, or roughly 0.0163871 liters.

Example 4: Converting cubic feet to cubic inches

A space measuring exactly one cubic foot converts to cubic inches by cubing the 12-inches-per-foot ratio:

$$1\ \text{ft}^3 = 12^3 = 1728\ \text{in}^3$$

So one cubic foot is 1728 cubic inches — a handy figure for moving between the two units.

Practical notes

1. The length × width × height formula only applies to rectangular (box-shaped) spaces. For cylinders, cones, or irregular shapes, use a dedicated volume tool.
2. Mixing units is fine — the calculator converts each dimension before multiplying — but double-check the unit selectors if a result looks too large or too small.
3. To go from cubic inches to cubic feet, divide by 1728; to go the other way, multiply by 1728.
4. For liquids, convert to liters or gallons; confirm whether a US gallon or a UK (imperial) gallon is required, since they differ by about 20%.

Frequently asked questions

How do I calculate cubic inches from length, width, and height?

Multiply the three dimensions together when they are all in inches: cubic inches = length (in) × width (in) × height (in). For a 2 in × 3 in × 4 in space that is $2 \times 3 \times 4 = 24\ \text{in}^3$.

How many cubic inches are in a cubic foot?

There are exactly 1728 cubic inches in one cubic foot, because $1\ \text{ft}^3 = 12^3 = 1728\ \text{in}^3$.

How do I convert cubic inches to cubic centimeters?

Multiply the number of cubic inches by 16.3871, since $1\ \text{in}^3 = 16.3871\ \text{cm}^3$.

How many cubic inches are in a liter?

One liter equals about 61.0237 cubic inches, since $1\ \text{in}^3 \approx 0.0163871\ \text{L}$.