What is a Cubic Foot?
A cubic foot (ft³) is a unit of volume equal to a cube measuring 1 foot (12 inches) on each side. It is commonly used in the United States and United Kingdom for measuring volume of spaces, containers, appliances, and materials.
One cubic foot equals 1,728 cubic inches, 7.48 US gallons, 6.23 UK gallons, or approximately 28.317 liters. In metric terms, 1 cubic foot equals 0.0283168 cubic meters.
Cubic feet are used to measure refrigerator capacity, shipping box sizes, room volume for HVAC sizing, storage unit capacity, and concrete or fill material quantities. Freight companies often use cubic feet to calculate dimensional weight for shipping.
How to Calculate Cubic Feet
Calculating cubic feet is straightforward: multiply three dimensions together. All measurements must be in feet. If you measured in other units, convert them to feet first.
Step 1: Measure the length, width, and height of the space or object.
Step 2: Convert all measurements to feet if needed. Divide inches by 12, multiply yards by 3, multiply meters by 3.28084, or divide centimeters by 30.48.
Step 3: Multiply length × width × height to get the volume in cubic feet.
Worked Example
A storage unit measures 10 ft long, 8 ft wide, and 8 ft high.
10 × 8 × 8 = 640 cubic feet. That is 640 / 27 = 23.7 cubic yards, or 640 × 0.0283168 = 18.12 cubic meters.
Unit Conversion Factors to Feet
| From | To Feet |
|---|---|
| Inches | Divide by 12 |
| Yards | Multiply by 3 |
| Meters | Multiply by 3.28084 |
| Centimeters | Divide by 30.48 |
Cubic Feet Conversion Table
Quick reference for converting cubic feet to other volume units.
| Cubic Feet | Cubic Inches | Cubic Yards | Cubic Meters | US Gallons |
|---|---|---|---|---|
| 1 ft³ | 1,728 | 0.0370 | 0.0283 | 7.48 |
| 5 ft³ | 8,640 | 0.1852 | 0.1416 | 37.40 |
| 10 ft³ | 17,280 | 0.3704 | 0.2832 | 74.81 |
| 25 ft³ | 43,200 | 0.9259 | 0.7079 | 187.01 |
| 50 ft³ | 86,400 | 1.8519 | 1.4158 | 374.03 |
| 100 ft³ | 172,800 | 3.7037 | 2.8317 | 748.05 |
| 500 ft³ | 864,000 | 18.5185 | 14.1584 | 3,740.26 |
| 1,000 ft³ | 1,728,000 | 37.0370 | 28.3168 | 7,480.52 |
Common Volume Estimates
Reference volumes for everyday items, shipping containers, and rooms to help you visualize cubic feet.
| Item / Space | Approx. Cubic Feet | Approx. Cubic Meters |
|---|---|---|
| Small shipping box (12×12×12 in) | 1.0 ft³ | 0.028 m³ |
| Medium shipping box (18×18×16 in) | 3.0 ft³ | 0.085 m³ |
| Large shipping box (24×24×24 in) | 8.0 ft³ | 0.227 m³ |
| Standard refrigerator | 18-25 ft³ | 0.51-0.71 m³ |
| Washing machine | 4-5 ft³ | 0.11-0.14 m³ |
| Small bedroom (10×10×8 ft) | 800 ft³ | 22.65 m³ |
| Average living room (15×20×8 ft) | 2,400 ft³ | 67.96 m³ |
| 5×10 storage unit (8 ft high) | 400 ft³ | 11.33 m³ |
| 10×10 storage unit (8 ft high) | 800 ft³ | 22.65 m³ |
| 20-ft shipping container | 1,172 ft³ | 33.18 m³ |
Quick Reference
Frequently Asked Questions
How do I calculate cubic feet from inches?
Measure length, width, and height in inches, then multiply all three and divide by 1,728. For example, a box 24 in × 18 in × 12 in = 5,184 cubic inches / 1,728 = 3.0 cubic feet. Alternatively, convert each dimension to feet first (divide by 12), then multiply.
How many cubic feet in a cubic yard?
There are exactly 27 cubic feet in one cubic yard. A cubic yard is 3 ft × 3 ft × 3 ft = 27 ft³. To convert cubic feet to cubic yards, divide by 27. To convert cubic yards to cubic feet, multiply by 27.
How many gallons in a cubic foot?
One cubic foot holds 7.48052 US liquid gallons or 6.22883 UK (imperial) gallons. To find gallons, multiply cubic feet by 7.48052 (US) or 6.22883 (UK). This is useful for aquariums, pools, and water tanks.
What is the difference between cubic feet and square feet?
Square feet (ft²) measures flat area (2D) while cubic feet (ft³) measures volume (3D). Square feet = length × width. Cubic feet = length × width × height. You need a height or depth measurement to convert between the two.
How do I calculate the cubic feet of a room?
Multiply the room's length × width × ceiling height, all in feet. A room 12 ft × 14 ft with 8-ft ceilings = 1,344 cubic feet. This is essential for HVAC sizing, air purifier selection, and understanding room volume for heating/cooling needs.
How do I convert cubic feet to cubic meters?
Multiply cubic feet by 0.0283168 to get cubic meters. For example, 100 ft³ × 0.0283168 = 2.83168 m³. To go the other way, multiply cubic meters by 35.3147 to get cubic feet.