What is a Cubic Foot (ft³)?
A cubic foot (ft³ or CFT) is a unit of volume equal to a cube measuring 1 foot (12 inches) on each side. It is widely used in the United States for measuring cargo volume, room sizes, storage units, and shipping containers.
In international shipping, cubic feet are often called CFT and are used alongside CBM (cubic metres). Many US freight carriers and 3PLs quote LTL rates using cubic feet rather than metres.
Cubic Feet Formula
Volume (ft³) = Length (ft) × Width (ft) × Height (ft)
From inches: (L" × W" × H") ÷ 1,728 = ft³
From cm: (L × W × H in cm) ÷ 28,317 = ft³
From CBM: CBM × 35.3147 = ft³
From inches: (L" × W" × H") ÷ 1,728 = ft³
From cm: (L × W × H in cm) ÷ 28,317 = ft³
From CBM: CBM × 35.3147 = ft³
Cubic Feet Conversion Table
| 1 Cubic Foot = | Value |
|---|---|
| Cubic Metres (m³ / CBM) | 0.028317 m³ |
| Cubic Inches (in³) | 1,728 in³ |
| Cubic Centimetres (cm³) | 28,316.8 cm³ |
| Litres | 28.317 L |
| US Gallons | 7.481 gallons |
Cubic Feet vs Cubic Metres in Shipping
Whether you use ft³ or m³ depends on your trade lane and carrier:
- US domestic LTL: Cubic feet (ft³) — freight class system
- International ocean freight: Cubic metres (CBM) — universal standard
- Air freight: Both CBM and ft³ used, volumetric weight formula differs
Our calculator shows both ft³ and CBM so you can use whichever your carrier requires.
Frequently Asked Questions
A 20ft GP container has approximately 1,172 ft³ (33.2 m³) of internal volume. A 40ft GP has about 2,387 ft³ (67.6 m³), and a 40ft HC has roughly 2,700 ft³ (76.4 m³).
Divide cubic feet by 35.3147 to get CBM. Example: 100 ft³ ÷ 35.3147 = 2.83 CBM. Use our Unit Converter for quick conversions.
A 10×10 ft storage unit with 8ft ceiling = 800 ft³. A 5×5 ft unit = 200 ft³. A 10×20 ft unit = 1,600 ft³. Use our Home Cubic Feet Calculator for room and storage sizing.