US Fluid Ounces to Cubic Inches (fl oz to in³)
1 US fluid ounce equals 1.8046875 cubic inches exactly.
How to convert US fluid ounces to cubic inches
To convert US fluid ounces to cubic inches, multiply the number of US fluid ounces by 1.8046875. This factor is exact. To go the other way, multiply cubic inches by 0.5541125541 (rounded).
cubic inches = US fluid ounces × 1.8046875
Example: 10 US fluid ounces = 18.046875 cubic inches.
Pints, quarts, gallons and fluid ounces differ between the US and the UK. Units are labeled 'US' or 'imperial' to avoid confusion.
About these units
US Fluid Ounce (fl oz)
One 128th of a US gallon, 29.5735 mL. Not the same as the weight ounce, and about 4% larger than the imperial fluid ounce.
Fluid ounce began as an attempt to link volume to weight: the volume occupied by one ounce of some substance, such as wine in England or water in Scotland. Definitions varied by region and by liquid. When Britain defined its imperial gallon in 1824 as the space of ten pounds of water, the imperial fluid ounce came out so that an ounce of water weighs about one avoirdupois ounce. The US fluid ounce followed a different path and comes from the older wine gallon.
The US fluid ounce is exactly 1/128 of a US gallon, 29.5735295625 milliliters, about 4 percent bigger than the imperial one at 28.4130625 milliliters. American nutrition labels use yet another figure, treating one fluid ounce as 30 milliliters, a convenient rounding for serving sizes. The name is a trap, because a fluid ounce measures space while a weight ounce measures mass. A US fluid ounce of water weighs a bit more than an ounce of weight, while a fluid ounce of honey weighs considerably more.
1 US fluid ounce = 0.02957352956 liters (approximately).
Sources: Wikipedia: Fluid ounce; NIST SP 811, Appendix B.8: conversion factors for volume; 21 CFR 101.9: nutrition labeling household measures
Cubic Inch (in³)
Exactly 16.387064 mL. Used for engine displacement in the US and for small mechanical parts.
Cubic inch is a unit defined by a ruler. Take an inch, build a cube, and its volume is exactly 16.387064 milliliters under the modern definition of the inch as 25.4 millimeters. Its main role in history is as the building block behind other US volumes: the US gallon is defined as 231 cubic inches, so a cubic inch is exactly 1/231 of a gallon. Even the 42-gallon oil barrel works out to precisely 9,702 of them.
The cubic inch survives most visibly in American engines, which are abbreviated c.i.d. for cubic inch displacement, while the rest of the world and many modern automakers speak in liters. A 5.7 liter engine is about 350 cubic inches, a conversion made easy by the exact factor of 16.387064. Small mechanical parts are also sized in cubic inches in North America.
1 cubic inch = 0.016387064 liters (exactly).
Sources: Wikipedia: Cubic inch; NIST SP 811, Appendix B.8: conversion factors for volume
Related conversions
- Cubic inches to US fluid ounces (reverse)
- US fluid ounces to liters
- US fluid ounces to milliliters
- US fluid ounces to US gallons
- US fluid ounces to US cups
- US fluid ounces to cubic meters
- US fluid ounces to cubic centimeters
- US fluid ounces to US quarts
- US fluid ounces to US pints
- US fluid ounces to US tablespoons
- US fluid ounces to US teaspoons
- US fluid ounces to metric cups
- US fluid ounces to metric tablespoons
- Liters to cubic inches
- Milliliters to cubic inches
- US gallons to cubic inches
- US cups to cubic inches
- Cubic meters to cubic inches
- Cubic centimeters to cubic inches
- US quarts to cubic inches
- US pints to cubic inches
- US tablespoons to cubic inches
- US teaspoons to cubic inches
- Metric cups to cubic inches
- Metric tablespoons to cubic inches
See all volume units.