Cubic Feet Calculator
Calculate the 3D volume of boxes, rooms, cylinders, and spheres in cubic feet (ft³). Instantly convert to cubic yards, gallons, liters, and cubic meters.
| Cubic Yards (yd³) | 17.78 Cu Yds |
| Cubic Inches (in³) | 829,440 Cu In |
| Cubic Meters (m³) | 13.59 m³ |
| Board Feet Lumber Equivalent | 5,760 Board Feet |
What is a Cubic Foot (cu ft / ft³)?
A Cubic Foot is a standard imperial unit of three-dimensional volume. It represents the space occupied by a cube whose sides each measure exactly one foot (12 inches) in length, width, and height.
Cubic feet calculations are widely used for shipping container volumes, refrigerator capacities, HVAC room air conditioning CFM sizing, storage units, and landscaping materials.
The Mathematics of 3D Spatial Volume
Here are the geometric formulas used to calculate cubic feet across common structures:
Volume (ft³) = Length (ft) * Width (ft) * Height (ft)
When measured in inches: Volume (ft³) = (Length in * Width in * Height in) / 1,728
Cylinder / Round Tank:
Volume (ft³) = π * (Radius in ft)^2 * Height (ft)
Sphere / Ball:
Volume (ft³) = (4 / 3) * π * (Radius in ft)^3
Unit Conversions:
1 Cubic Foot = 1,728 Cubic Inches = 0.037037 Cubic Yards = 7.48052 US Gallons = 28.3168 Liters = 0.0283168 m³
Step-by-Step Worked Example
Suppose you have a shipping crate measuring 24 inches long, 18 inches wide, and 12 inches high:
- Calculate cubic inches:
24 * 18 * 12 = 5,184 cubic inches. - Divide by 1,728 (the number of in³ in 1 ft³):
5,184 / 1,728 = 3.0 Cubic Feet. - Convert to US Gallons:
3.0 * 7.4805 = 22.44 Gallons. - Convert to Cubic Yards:
3.0 / 27 = 0.111 Cubic Yards.
Master Cubic Feet Conversion Reference Table
Direct equivalents from cubic feet to other common volume units:
| Cubic Feet (ft³) | Cubic Yards (yd³) | US Gallons | Liters (L) | Cubic Meters (m³) |
|---|---|---|---|---|
| 1 ft³ | 0.037 yd³ | 7.48 gal | 28.32 L | 0.028 m³ |
| 5 ft³ | 0.185 yd³ | 37.40 gal | 141.58 L | 0.142 m³ |
| 27 ft³ (1 Cu Yd) | 1.000 yd³ | 201.97 gal | 764.55 L | 0.765 m³ |
| 50 ft³ | 1.852 yd³ | 374.03 gal | 1,415.84 L | 1.416 m³ |
| 100 ft³ | 3.704 yd³ | 748.05 gal | 2,831.68 L | 2.832 m³ |
| 500 ft³ | 18.519 yd³ | 3,740.26 gal | 14,158.42 L | 14.158 m³ |
| 1,000 ft³ | 37.037 yd³ | 7,480.52 gal | 28,316.85 L | 28.317 m³ |
Practical Real-World Applications
- Moving & Storage Units: A standard 10x10 storage unit with 8-foot ceilings offers 800 cubic feet of packing space.
- HVAC Airflow Sizing (CFM): Air conditioner and furnace sizing depends on total room volume in cubic feet to calculate necessary air changes per hour.
- Freight Shipping Dimensional Weight: Logistics carriers calculate dimensional (DIM) weight based on total cubic volume to price parcel shipments.
- Appliance Capacity: Refrigerators, freezers, washing machines, and microwaves are rated in internal usable cubic feet.
5 Tips for Accurate Volume Measuring
Frequently Asked Questions
Multiply length in inches by width in inches by height in inches to find total cubic inches, then divide by 1,728 (the number of cubic inches in one cubic foot). Formula: Cubic Feet = (Length in * Width in * Height in) / 1,728.
One cubic foot equals exactly 7.48052 US liquid gallons (or 28.3168 liters).
There are exactly 27 cubic feet in one cubic yard (3 ft * 3 ft * 3 ft = 27 ft³).
Square feet measures two-dimensional surface area (Length * Width). Cubic feet measures three-dimensional volumetric space (Length * Width * Height).
A standard 20-foot intermodal shipping container (approx 19'4" L x 7'8" W x 7'9" H interior) provides approximately 1,165 to 1,172 cubic feet of internal storage volume.