Cubic Inches to Cubic Feet Calculator
1 cubic foot equals 1,728 cubic inches. Type in either field for instant bidirectional conversion.
Why 1,728?
A cubic foot is a cube 12 inches on each side. The volume is 12 × 12 × 12 = 1,728 in³. To convert cubic inches to cubic feet, divide by 1,728. To go the other way, multiply by 1,728.
Common Applications
Packaging & Boxes
Shipping cartons and small package dimensions are quoted in inches. Multiply L × W × H in inches to get cubic inches, then divide by 1,728 for cubic feet (used for freight density and dimensional weight).
Engine Displacement
Classic American engines are rated in cubic inches (e.g., 350 CID). Convert to liters by dividing by 61.024: 350 CID = 5.7 L. To convert to cubic feet, divide by 1,728 (a 350 CID engine displaces 0.2025 ft³).
Speaker & Subwoofer Boxes
Audio enclosures are precisely tuned to internal volume in cubic feet, but built and measured in inches. Calculate the inside dimensions in inches, multiply, and divide by 1,728. Subtract driver and port displacement for net volume.
Conversion Table
| Cubic Inches | Cubic Feet |
|---|---|
| 100 | 0.0579 |
| 500 | 0.2894 |
| 864 | 0.5 |
| 1,000 | 0.5787 |
| 1,728 | 1 |
| 2,500 | 1.447 |
| 5,000 | 2.894 |
| 8,640 | 5 |
| 10,000 | 5.787 |
| 17,280 | 10 |
Worked Example
A subwoofer box has internal dimensions 28 in × 16 in × 14 in. Cubic inches: 28 × 16 × 14 = 6,272 in³. Cubic feet: 6,272 ÷ 1,728 = 3.63 ft³. Subtract 0.15 ft³ for driver displacement → 3.48 ft³ net.
Building a Subwoofer Box? Start Here
Speaker and subwoofer enclosures are designed in cubic feet but measured and cut in inches, which is why this conversion comes up constantly in car audio and home theater builds. Measure the internal box dimensions in inches, subtract for wood thickness on each side, multiply the three internal numbers together, then divide by 1,728. The storage calculator has a dedicated subwoofer box section with net-volume adjustment for driver and port displacement built in, so you don't need to do the subtraction by hand.
Frequently Asked Questions
How many cubic inches in a cubic foot?
1,728 cubic inches equal 1 cubic foot (12 × 12 × 12 = 1,728).
How do I convert cubic inches to cubic feet?
Divide cubic inches by 1,728.
What is 5,000 cubic inches in cubic feet?
5,000 ÷ 1,728 = 2.894 ft³.
How do I find cubic inches of a box?
Multiply length × width × height in inches.
Why do speaker boxes use cubic inches?
Sub enclosures need precise small volumes; cubic inches give finer resolution than cubic feet.
How do I convert engine displacement?
Engine displacement in CID (cubic inches) ÷ 61.024 = liters.
What is 1 cubic foot in cubic inches?
1 ft³ = 1,728 in³.
How to convert in³ to liters?
Multiply cubic inches by 0.01639 to get liters.