Convert Cups (US) to Fluid Ounces (US)
Cup (US) (cup) to Fluid Ounce (US) (fl oz) unit conversion — enter any value below to get an instant result, or use the table for common values.
Results from this calculator are estimates provided for general informational purposes only, based on formulas, rates, and standards commonly accepted as of 2026. Figures may differ slightly from other calculators or professional sources due to rounding methods, differing assumptions, or regional regulations, and rules may change over time. Always consult a qualified professional — such as a financial advisor, healthcare provider, or other relevant specialist — before making decisions based on these results.
Result
1 cup = 8 fl oz
1 Cup (US) = 8 Fluid Ounces (US)
1 Fluid Ounce (US) = 0.125 Cups (US)
1 cup in every supported unit
Conversion chart: Cup (US) to Fluid Ounces (US)
Conversion table
| Cup (US) (cup) | Fluid Ounce (US) (fl oz) |
|---|---|
| 0.01 cup | 0.08 fl oz |
| 0.1 cup | 0.8 fl oz |
| 1 cup | 8 fl oz |
| 2 cup | 16 fl oz |
| 3 cup | 24 fl oz |
| 5 cup | 40 fl oz |
| 10 cup | 80 fl oz |
| 20 cup | 160 fl oz |
| 50 cup | 400 fl oz |
| 100 cup | 800 fl oz |
| 1000 cup | 8000 fl oz |
Cup (US) (cup)
Definition: A US customary cooking measure equal to 8 US fluid ounces, or exactly 236.5882365 milliliters.
History: Standardized in the early 20th century by American cookbook authors and home economists (notably Fannie Farmer) to bring consistency to recipe measurements that had previously varied by household.
Current use: Almost exclusively a cooking and baking unit in the United States; most other countries measure recipe ingredients by weight (grams) rather than cup volume.
Fluid Ounce (US) (fl oz)
Definition: A US customary unit of volume equal to 1/128 of a US gallon, or exactly 29.5735296 milliliters.
History: Descended from old English wine-trade measures; the US retained the older English wine gallon standard after independence, while the UK later redefined its own imperial fluid ounce differently in 1824 — leaving the two "fluid ounce" units slightly different sizes today.
Current use: Used throughout the US for beverage can and bottle sizes, cooking recipes, and nutrition labeling.
Supported Units
| Unit | Symbol | In Liters |
|---|---|---|
| Milliliter | mL | 0.001 L |
| Liter | L | 1 L |
| Cubic Meter | m³ | 1000 L |
| Cubic Foot | ft³ | 28.316847 L |
| Cubic Inch | in³ | 0.016387064 L |
| Fluid Ounce (US) | fl oz | 0.02957353 L |
| Cup (US) | cup | 0.23658824 L |
| Pint (US) | pt | 0.47317647 L |
| Quart (US) | qt | 0.94635295 L |
| Gallon (US) | gal | 3.7854118 L |
About These Parameters
- Value
- The number you want to convert, expressed in the "From" unit. Accepts decimals.
- From Unit
- The unit your input value is currently measured in.
- To Unit
- The unit you want the result converted into. Use the swap button to flip From and To instantly.
How Volume Conversion Works
The Formula
Every unit here is defined by a fixed multiplier relative to the liter. To convert a value from one unit to another:
result = value × (factor of "From" unit ÷ factor of "To" unit)
For Cup (US) → Fluid Ounce (US): multiply by 8. For example, 1 cup × 8 = 8 fl oz.
US Gallons vs. UK Imperial Gallons
This converter uses US customary volume units exclusively (fluid ounce, cup, pint, quart, gallon), which are not the same size as their UK imperial counterparts. A US gallon is exactly 3.785411784 liters, while a UK imperial gallon is about 4.546 liters — roughly 20% larger. Both systems trace back to old English measures, but the US kept the older wine-gallon standard after 1776 while Britain redefined its units in 1824. This mismatch is a common source of confusion when comparing fuel economy or recipe measurements between the US and UK.
Metric vs. US Customary Volume
The metric units on this page (milliliter, liter, cubic meter) all scale by powers of ten, so converting between them is just moving a decimal point. US customary units (fluid ounce, cup, pint, quart, gallon) use irregular multiples — 8 fluid ounces to a cup, 2 cups to a pint, 2 pints to a quart, 4 quarts to a gallon — inherited from centuries-old English liquid-measure tradition rather than a decimal system.
Volume in the Kitchen
Cups, pints, and quarts are primarily cooking and baking units in the United States — most other countries measure recipe ingredients by weight (grams) instead, which is more precise because ingredients like flour can pack differently depending on how they're scooped. When following a recipe written in cups or fluid ounces, converting to milliliters first can help if you're using a metric kitchen scale or measuring jug.
Example
1 cup equals 8 fl oz. For scale, that's about 0.24× a standard 1-liter water bottle (1 L, or 4.2267528 cup).
Frequently Asked Questions
How many Fluid Ounces (US) are in 1 Cup (US)?
1 Cup (US) (cup) equals exactly 8 Fluid Ounces (US) (fl oz).
Why is a US gallon smaller than a UK gallon?
The US kept the older English wine gallon (231 cubic inches, about 3.785 L) after independence, while the UK redefined its gallon in 1824 based on the volume of 10 pounds of water (about 4.546 L) — the two countries never reconciled the difference, so today "gallon" means two different volumes depending on where you are.
How many milliliters are in a US cup?
One US cup equals exactly 236.5882365 milliliters, though many recipes and kitchen tools round this to 240 mL for simplicity.
Is a cubic centimeter the same as a milliliter?
Yes — one cubic centimeter (cm³ or cc) is exactly equal to one milliliter by definition, which is why medical dosing is often labeled in either unit interchangeably.