Cubic Footage Calculator

What is a cubic footage calculator?

Cubic footage is the volume of a three-dimensional space measured in cubic feet (symbol: ft³ or cu ft). One cubic foot is the volume of a cube whose edges are each one foot long. Where square footage describes a flat area such as a floor, cubic footage describes how much space a room, box, container, or excavation actually holds.

A cubic footage calculator takes the three perpendicular dimensions of a rectangular (box-shaped) space — its length, width, and height (or depth) — and multiplies them to return the volume. It is the everyday tool for sizing rooms for heating and cooling, estimating the capacity of a moving truck or shipping crate, ordering bulk materials like soil, mulch, or gravel, and checking whether furniture or appliances will fit.

How does the calculator work?

For any rectangular box, the volume is the product of its three dimensions. Enter the length, the width, and the height — by default all in feet — and the calculator multiplies them together. Because the dimensions are already in feet, the result comes straight out in cubic feet, with no extra conversion needed. If any one of the three dimensions is left blank, no result is shown, because the volume of a box is undefined until all three sides are known.

Formula

The cubic footage $V$ of a rectangular space is:

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

where:

• $l$ is the length in feet,
• $w$ is the width in feet,
• $h$ is the height or depth in feet.

When all three measurements are in feet, the product is already expressed in cubic feet. If you need the answer in another unit, recall that:

$$1\ \text{ft}^3 = 0.0283168\ \text{m}^3 = 28.3168\ \text{L} = 0.037037\ \text{yd}^3$$

Because there are 27 cubic feet in a cubic yard, dividing the cubic footage by 27 gives the volume in cubic yards — the unit often used when ordering concrete or landscaping materials.

Worked examples

Example 1: A standard room

A room measures 10 ft long, 10 ft wide, and 8 ft high. Its cubic footage is:

$$V = 10 \times 10 \times 8 = 800\ \text{ft}^3$$

So the room encloses 800 cubic feet of space — a useful figure for sizing an air conditioner or estimating airflow.

Example 2: A larger room

A living room measures 12 ft by 10 ft with a 9 ft ceiling:

$$V = 12 \times 10 \times 9 = 1080\ \text{ft}^3$$

The room holds 1,080 cubic feet.

Example 3: A one-foot cube

A box that is one foot on every side has the smallest whole-foot volume:

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

This single cubic foot is the building block all larger volumes are measured against.

Practical notes

1. The length × width × height formula applies only to rectangular, box-shaped spaces. For cylinders, cones, or irregular rooms, split the space into rectangular sections or use a dedicated volume tool.
2. Keep every dimension in the same unit before multiplying. Mixing feet and inches without converting first is the most common source of error.
3. To convert cubic footage to cubic yards for bulk material orders, divide by 27, since 1 cubic yard equals 27 cubic feet.
4. For ceiling height, measure from the finished floor to the ceiling; for storage and excavation, use the full depth of the space.

Frequently asked questions

How do I calculate cubic footage?

Multiply length, width, and height when all three are in feet: cubic footage = length (ft) × width (ft) × height (ft). For a 10 ft × 10 ft × 8 ft room that is $10 \times 10 \times 8 = 800\ \text{ft}^3$.

What is the difference between square footage and cubic footage?

Square footage measures a flat, two-dimensional area (length × width) and is reported in ft². Cubic footage measures a three-dimensional volume (length × width × height) and is reported in ft³. Multiply a room’s square footage by its ceiling height to get its cubic footage.

How do I convert cubic feet to cubic yards?

Divide the number of cubic feet by 27, because $1\ \text{yd}^3 = 27\ \text{ft}^3$. For example, 800 ft³ is about 29.6 cubic yards.