Volume conversion
US customary cup to US fluid ounce converter
Convert cup to fl oz instantly, choose the displayed precision, and verify the result with the formula and reference table below.
US fluid ounce (fl oz)
Rounded for display only; calculations retain full precision.
Rounding and precision rules
- Convr calculates first and rounds the displayed result only once, at the final step.
- The default is a maximum of 6 decimal places; trailing zeros are removed.
- Very small values that would appear as zero, and values of 10¹² or more, use scientific notation.
- Display precision is not measurement uncertainty. For scientific, engineering, or regulated work, retain only the digits justified by the source measurement.
Calculation
US customary cup to US fluid ounce formula
fl oz = cup × 8
Calculations retain full precision and the result is rounded only for display.
Worked example
For 10 cup, the result is 80 fl oz. Substitute 10 cup into the formula to obtain 80 fl oz.
A numerical value expressed in us fluid ounce is usually larger than the same measurement expressed in us customary cup, because 1 cup equals 8 fl oz.
US customary cup to US fluid ounce reference table
Common values rounded to a maximum of 6 decimal places.
| US customary cup (cup) | US fluid ounce (fl oz) |
|---|---|
| 1 cup | 8 fl oz |
| 5 cup | 40 fl oz |
| 10 cup | 80 fl oz |
| 50 cup | 400 fl oz |
| 100 cup | 800 fl oz |
Understanding the units
About US customary cup and US fluid ounce
US customary cup (cup)
One us customary cup (cup) equals 0.236588237 L, the base relationship used for this volume conversion.
US fluid ounce (fl oz)
One us fluid ounce (fl oz) equals 0.02957353 L, the base relationship used for this volume conversion.
When this conversion is useful
US customary cup to US fluid ounce conversion is useful for recipes, beverage quantities, fuel volumes, laboratory measurements, and container capacities. It lets you compare the same volume or capacity across documents, tools, or standards that use different units.
Learn with Convr
Conversion guides
Metric vs Imperial Units: A Practical Comparison
Understand how metric, US customary, and Imperial units differ, where each system is used, and how to convert between them reliably.
Read guide →Everyday conversionsUS Gallons vs Imperial Gallons: What Is the Difference?
Compare US liquid gallons and Imperial gallons, understand their exact liter values, and avoid common fuel and recipe conversion errors.
Read guide →Answers at a glance
Frequently asked questions
How do you convert US customary cup to US fluid ounce?
Use the formula fl oz = cup × 8. Enter any value in the converter above to calculate the result instantly.
How many us fluid ounce are in one us customary cup?
One us customary cup equals 8 us fluid ounce.
How does Convr round US customary cup to US fluid ounce results?
Convr keeps full numeric precision during the calculation and rounds only the displayed result. The default is a maximum of 6 decimal places, with selectable precision on this page.
Can I convert negative or decimal us customary cup values?
Yes. The converter accepts positive, negative, decimal, and scientific-notation values. Negative values are physically meaningful for some scales, such as temperature, but not for every measured quantity.
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