21 Ounces to Cups

21 fl oz = 2.625 cup

Calculation: cup = 21 fl oz × 0.125 = 2.625 cup

Ounce to Cup Converter

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How much is 21 fl oz?

621 mL (21 fl oz) is about a standard wine bottle (750 mL / 25.4 fl oz).

What does 21 fl oz look like?

Illustration of a wine bottle
621 mL (21 fl oz) is about a standard wine bottle (750 mL / 25.4 fl oz).

21 fl oz on the cup scale

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21 fl oz = 2.625 cup

How to Convert Ounce to Cup

1 ounce = 18 cups

Cup = Ounce × 18

Example: 21 fl oz × 18 = 2 58 cup

Reverse Conversion

To convert cups back to ounces:

  • Remember, 1 cup equals 8 ounces.
  • To convert 2 58 cup to fl oz, multiply 2 58 x 8, resulting in 21 fl oz.

21 fl oz is also equal to:

Frequently Asked Questions

How much is 21 ounces in cups?

21 ounces equals 2.625 cups. This is calculated by multiplying 21 by the conversion factor 0.125.

What does 21 ounces look like in cups?

21 ounces (2.625 cups) is a pint to a quart — a large glass or a small bottle.

How do you calculate 21 ounces to cups?

Multiply 21 by the conversion factor 0.125. The calculation is 21 × 0.125 = 2.625 cups. This factor is defined by international measurement standards.

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21 ounces = 2.625 cups
21 ounces = 2.625 cups — conversion chart

Nearby Conversions

1 ounce0.125 cups 5 ounces0.625 cups 9 ounces1.125 cups 13 ounces1.625 cups 17 ounces2.125 cups 25 ounces3.125 cups 29 ounces3.625 cups 33 ounces4.125 cups 37 ounces4.625 cups 41 ounces5.125 cups 45 ounces5.625 cups 49 ounces6.125 cups 53 ounces6.625 cups 57 ounces7.125 cups 61 ounces7.625 cups

For general conversions between ounces and cups, see the ounces to cups converter.

Also convert Ounces to:

Conversion factors verified against NIST, BIPM, ISO 80000-3 1 US gallon = 3.785411784 L (exact, US customary). Last reviewed: March 2026
Adilson Fernandes By Adilson Fernandes
Tiago Fernandes Reviewed by Tiago Fernandes

All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.