Volume · Unit Converter

Convert US Cup to US Fluid Ounce

Convert us cups to us fluid ounces instantly. 1 us cup = 8 us fluid ounce — use the live calculator, the exact formula, a conversion table and worked examples. Also check the US Fluid Ounce to US Cup converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Dr. Jaya Christiyan K G, Ph.D.
Volume category 2 min read Published Last reviewed Updated

Units explained

US Customary (Liquid)

US Cup

What is a us cup?

A US customary cup is one sixteenth of a US gallon (236.588 mL).

Origin of the us cup

Standardized for American cooking; distinct from the 240 mL US legal cup and the 250 mL metric cup.

Where it is used

The standard US cooking-volume unit in recipes.

When and where it was developed

US customary cooking measure.

US Customary (Liquid)

US Fluid Ounce

What is a us fluid ounce?

A US fluid ounce is 1/128 of a US gallon (29.5735 mL).

Origin of the us fluid ounce

Derived from the gallon subdivision; distinct from the slightly smaller UK fluid ounce.

Where it is used

Standard for US beverage and nutrition labeling.

When and where it was developed

English customary; US since 1824.

US Cup to US Fluid Ounce conversion formula

The relationship between us cups and us fluid ounces:

1 cup = 8 fl oz
1 fl oz = 0.125 cup

To convert us cups to us fluid ounces, multiply the value in us cups by 8. To reverse, multiply us fluid ounces by 0.125.

How to use this converter

Type a value into the calculator. The result in us fluid ounces updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the US Fluid Ounce to US Cup converter for the reverse direction.

Step-by-step: convert us cups to us fluid ounces

  1. Write down the value in us cups (cup).
  2. Multiply that value by the factor 8.
  3. The product is the equivalent value in us fluid ounces (fl oz).
  4. To reverse, multiply the us fluid ounce value by 0.125.

Worked examples

Example 1 — Convert 1 cup to fl oz:
1 × 8 = 8 fl oz

Example 2 — Convert 100 cup to fl oz:
100 × 8 = 800 fl oz

Real-world example — Plastic-film thickness alternates

A 150-us cup plastic film converts cleanly to us fluid ounces — useful for packaging buyers reconciling supplier datasheets across metric and US measurement systems.

150 cup × 8 = 1200 fl oz

Real-world example — Hair-width scale measurements

A 70-us cup measurement (about the diameter of a human hair) is the kind of value materials engineers regularly express in adjacent micro-scale units like us fluid ounces for direct comparison across supplier datasheets.

70 cup × 8 = 560 fl oz

Real-world example — Paper and film thicknesses

At the thickness of office paper (roughly 3 us cups), converting between sub-millimeter units is routine for packaging and printing buyers comparing quotes from metric and US suppliers.

3 cup × 8 = 24 fl oz

US Cup to US Fluid Ounce conversion table

Standard reference values for converting us cups to us fluid ounces:

US Cup [cup]US Fluid Ounce [fl oz]
0.010.08
0.10.8
18
216
324
432
540
1080
20160
30240
40320
50400
100800
5004000
10008000

Frequently asked questions

How many us fluid ounces is 1 us cup?
1 us cup equals 8 us fluid ounce.
How do I convert us cups to us fluid ounces?
Multiply the value in us cups by 8 to get us fluid ounces.
How do I convert us fluid ounces back to us cups?
Multiply the value in us fluid ounces by 0.125, or use the US Fluid Ounce to US Cup converter.
How many us fluid ounces is 100 us cups?
100 us cups equals 800 us fluid ounces, because 100 × 8 = 800.

Convert US Cup to other volume units

Show all US Cup conversions

Sources & references

Conversion factor (1 cup = 8 fl oz) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.