Cubic Inches Calculator
Enter length, width and height. A box 12 × 10 × 8 inches holds 960 cubic inches.
Sources: NIST SP 811, NIST Handbook 44 Updated
Result
12 × 10 × 8 in = 960 in³
= 0.555556 ft³
= 15,731.6 cm³ (mL) = 15.7316 L
= 4.15584 US gal
The formula
cubic inches = length × width × height (all in inches)
Fractions work too: type 3 5/8 or 3.625. If the sides are in another unit, the calculator converts each one to inches with the exact factor (1 ft = 12 in, 1 in = 2.54 cm) before multiplying.
Worked example: a 12 × 10 × 8 inch box
- Multiply length by width: 12 × 10 = 120 square inches (the base).
- Multiply by the height: 120 × 8 = 960 cubic inches.
- In other units: 960 ÷ 1,728 = 0.5556 cubic feet, 960 ÷ 231 = 4.156 US gallons, 960 × 16.387064 = 15,731.6 cm³.
Cubic inches in other units
| Cubic inches | Cubic feet | Liters | US gallons |
|---|---|---|---|
| 1 | 0.0006 | 0.016 | 0.004 |
| 10 | 0.0058 | 0.164 | 0.043 |
| 61 | 0.0353 | 1.000 | 0.264 |
| 100 | 0.0579 | 1.639 | 0.433 |
| 231 | 0.1337 | 3.785 | 1.000 |
| 500 | 0.2894 | 8.194 | 2.165 |
| 1,000 | 0.5787 | 16.387 | 4.329 |
| 1,728 | 1.0000 | 28.317 | 7.481 |
| 5,000 | 2.8935 | 81.935 | 21.645 |
231 cubic inches is exactly one US gallon and 1,728 cubic inches exactly one cubic foot.
Frequently asked questions
How do I calculate cubic inches?
Multiply length × width × height, with all three measured in inches. A box 12 in long, 10 in wide and 8 in tall is 12 × 10 × 8 = 960 cubic inches.
How many cubic inches are in a cubic foot?
1,728, because a cubic foot is 12 × 12 × 12 inches. To turn cubic inches into cubic feet, divide by 1,728.
How many cubic inches are in a gallon?
A US gallon is exactly 231 cubic inches. To turn cubic inches into US gallons, divide by 231.
My measurements are in feet or centimeters. What do I do?
Pick the unit in “Measured in”. The calculator converts each side to inches first and then multiplies, so the answer is still in cubic inches. All three sides must be in the same unit.
Does this work for a cylinder or an odd shape?
No. Length × width × height is the volume of a rectangular box. A cylinder is π × radius² × height. For an irregular shape, split it into boxes and add the volumes.
Sources
- NIST Special Publication 811, Appendix B.8 — 1 cubic inch = 16.387064 cm³ exactly (checked October 12, 2026)
- NIST Handbook 44 (2026), Appendix C — 1,728 cubic inches = 1 cubic foot; 1 US gallon = 231 cubic inches (checked October 12, 2026)