A cubic inch is the volume of a one-inch cube.
Cubic inches to Imperial fluid ounces Converter — in3 to imp fl oz
Convert Cubic inch (in3) to Imperial fluid ounce (imp fl oz) using the exact conversion factor (1 cubic inch = 0.576744024 imperial fluid ounce). See the formula, worked examples, conversion table, history, and common uses.
Cubic inches to Imperial fluid ounces converter
Converter
Volume Converter
Convert metric, US customary, imperial, cooking, dry, and industrial volume units.
Context values
Some unit families need one extra value for a physically accurate result.
An imperial fluid ounce is 1/160 of an imperial gallon.
Result = input x 1.6387064e-5 / 2.84130625e-5.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Cubic inches to Imperial fluid ounces
Cubic inch and Imperial fluid ounce appear side by side at fuel pumps and on beverage labels, since the US measures liquids in gallons while most of the world uses liters. Specifically: A cubic inch is the volume of a one-inch cube, and an imperial fluid ounce is 1/160 of an imperial gallon.
Formula
imperial fluid ounces = cubic inches × 0.576744023985
This factor comes from each unit's defined relationship to the category's base unit: 1 cubic inch equals 0.000016387064 base units, and 1 imperial fluid ounce equals 0.0000284130625 base units, so dividing one by the other gives the direct cubic inch-to-imperial fluid ounce factor of 0.576744023985.
Simple example
1 in3 × 0.576744024 = 0.576744024 imp fl oz
1 cubic inch = 0.576744024 imperial fluid ounces.
Real-world example
10 in3 × 0.576744024 = 5.76744024 imp fl oz
10 cubic inches = 5.76744024 imperial fluid ounces.
Conversion table
| Cubic inch (in3) | Imperial fluid ounce (imp fl oz) |
|---|---|
| 1 in3 | 0.576744024 imp fl oz |
| 5 in3 | 2.88372012 imp fl oz |
| 10 in3 | 5.76744024 imp fl oz |
| 25 in3 | 14.4186006 imp fl oz |
| 50 in3 | 28.8372012 imp fl oz |
| 100 in3 | 57.6744024 imp fl oz |
Reverse conversion: Imperial fluid ounce to Cubic inch
0.576744024 imp fl oz × 1.733871455 = 1 in3
0.576744024 imperial fluid ounces = 1 cubic inches.
cubic inches = imperial fluid ounces × 1.73387145495
For a page dedicated to this direction, see Imperial fluid ounce to Cubic inch.
Understanding the Cubic inch (in3)
A cubic inch is the volume of a one-inch cube.
Understanding the Imperial fluid ounce
Imperial fluid ounce (imp fl oz) measures volume. The imperial fluid ounce is 1/160 of an imperial gallon: exactly 28.4130625 milliliters — slightly smaller than the US fluid ounce despite the larger imperial gallon, because it divides that gallon into more parts. It is classified as a UK/imperial customary unit.
Where it's used: United Kingdom (historically; less common in current UK retail than metric units)
Imperial fluid ounce vs. US fluid ounce. Confusingly, the imperial fluid ounce (28.41 mL) is slightly smaller than the US fluid ounce (29.57 mL), even though the imperial gallon is larger overall — because the imperial gallon is divided into 160 fluid ounces rather than the US gallon's 128.
Uses of the Imperial fluid ounce today
- UK/Commonwealth beverage measurement in historical or specialized contexts
History of the Imperial fluid ounce
The imperial fluid ounce follows from Britain's 1824 imperial gallon, divided into 160 parts rather than the 128 used in the US system, producing its counterintuitively smaller size relative to the US fluid ounce.
Historical origin. Imperial fluid ounce was not the invention of a single named person; it developed through the process described above.
Imperial fluid ounce — sources
- UK Weights and Measures Act 1824 — Basis for the imperial fluid ounce via the imperial gallon.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many imperial fluid ounces are in 1 cubic inch?
1 cubic inch equals 0.576744024 imperial fluid ounces, using the exact defined conversion factor rather than an estimate.
How do I convert cubic inch to imperial fluid ounce?
Multiply the cubic inch value by 0.576744024. The converter above does this instantly to whatever precision you set.
How do I convert imperial fluid ounce back to cubic inch?
Use the reverse factor: 1 imperial fluid ounce equals 1.733871455 cubic inches. You can also use the swap control in the converter above to flip the direction instantly.
What is a cubic inch?
Cubic inch (in3) is a unit of volume.
What is a imperial fluid ounce?
Imperial fluid ounce (imp fl oz) measures volume. The imperial fluid ounce is 1/160 of an imperial gallon: exactly 28.4130625 milliliters — slightly smaller than the US fluid ounce despite the larger imperial gallon, because it divides that gallon into more parts. It is classified as a UK/imperial customary unit.
Is the cubic inch to imperial fluid ounce conversion exact?
Yes. The imperial fluid ounce is 1/160 of an imperial gallon: exactly 28.4130625 milliliters — slightly smaller than the US fluid ounce despite the larger imperial gallon, because it divides that gallon into more parts. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between imperial fluid ounce vs. us fluid ounce?
Confusingly, the imperial fluid ounce (28.41 mL) is slightly smaller than the US fluid ounce (29.57 mL), even though the imperial gallon is larger overall — because the imperial gallon is divided into 160 fluid ounces rather than the US gallon's 128.