# Cups to Fluid Ounces Converter URL: https://speedycalculator.com/calculators/conversion/cups-to-oz/ Last updated: 2026-10-25 > Convert US cups (US cup) to US fluid ounces (US fl oz): 1 US cup = 8 US fl oz, so multiply by 8 or divide by 0.125. Both fields are editable, so you can also type in US fluid ounces and get US cups back. ## Inputs - US cups (US cup) ## Results - US fluid ounces ## Formula ``` 1 US cup = 8 US fl oz 1 US fl oz = 0.125 US cup US fl oz = US cup × 8 ``` ## Explanation A U.S. cup is 8 fluid ounces. For dry ingredients, a cup of flour weighs only about 4.4 ounces, so use a weight converter instead. ### How to use the Cups to Fluid Ounces Converter - Type the number of US cups into the **US cups** field. Decimals such as 0.5 are fine. - Read the answer in **US fluid ounces** – it updates as you type, with no button to press. - To convert the other way, type into **US fluid ounces** and the US cups are recalculated. - Press **Copy results** to copy both values with the page title, or **Copy link** to share this exact conversion. This page converts only US cup ⇄ US fl oz. Need a different unit? Use the general volume converter, where you can choose any “from” and “to” unit. ### How it works Both units measure volume, so they are always in the same ratio: one US cup equals 8 US fluid ounces. The calculator multiplies the number of US cups you type by 8 to give US fluid ounces, and when you type into the US fluid ounces field it divides by the same factor to give US cups. Because the ratio never changes, doubling the US cups always doubles the US fluid ounces. Results are calculated at full precision and rounded only for display (up to eight decimal places, with very large or small values shown in scientific notation). ### How to convert US cups to US fluid ounces - Write down the value in US cups, for example **1 US cup**. - Multiply by the conversion factor 8 (because 1 US cup = 8 US fl oz). - 1 × 8 = **8 US fl oz**. - To go back from US fluid ounces to US cups, divide by 8 – or multiply by 0.125. ### US cup to US fl oz conversion table US cupsUS fluid ouncesUS fluid ouncesUS cups0.25 US cup2 US fl oz1 US fl oz0.125 US cup0.33 US cup2.64 US fl oz2 US fl oz0.25 US cup0.5 US cup4 US fl oz5 US fl oz0.625 US cup0.67 US cup5.36 US fl oz10 US fl oz1.25 US cup0.75 US cup6 US fl oz20 US fl oz2.5 US cup1 US cup8 US fl oz50 US fl oz6.25 US cup1.5 US cup12 US fl oz100 US fl oz12.5 US cup2 US cup16 US fl oz1,000 US fl oz125 US cup3 US cup24 US fl oz4 US cup32 US fl oz ### What is a US cup? The U.S. customary cup is 8 U.S. fluid ounces, about 236.6 mL. Recipes from Australia, Canada and New Zealand often use the 250 mL metric cup instead. ### What is a US fluid ounce? The U.S. fluid ounce is 1/128 of a U.S. gallon, about 29.57 mL. It is a unit of volume: a fluid ounce of water weighs about one ounce, but other liquids do not. ### Common mistakes to avoid Mixing u.s. and uk gallons, pints and fluid ounces, assuming a cup is always 250 ml, and treating volume and weight as interchangeable for anything except water. ## Worked example Inputs — US cups: 1 US cup. Results — **US fluid ounces = 8 US fl oz**. ## FAQ **How many fl oz in a cup?** 8. **How many fl oz in 3/4 cup?** 6 fl oz. **How many US fluid ounces are in one US cup?** 1 US cup = 8 US fl oz. **How many US cups are in one US fluid ounce?** 1 US fl oz = 0.125 US cup. **How do I convert US cups to US fluid ounces?** Multiply the number of US cups by 8. For example, 1 US cup × 8 = 8 US fl oz. **How do I convert US fluid ounces back to US cups?** Divide by 8 (or multiply by 0.125), or simply type the value into the US fluid ounces field above. **What is 2 US cup in US fluid ounces?** 2 US cup = 16 US fl oz. **Is this conversion exact?** Yes. The factor comes from the official definitions of both units (NIST and the SI), so the only difference you may see is rounding in the last displayed digit. **Can I convert to other units on this page?** This page converts only between US cups and US fluid ounces. To pick any volume unit, use the general volume converter linked under Related calculators. **What formula does the Cups to Fluid Ounces Converter use?** 1 US cup = 8 US fl oz. ## Sources - [NIST Special Publication 811 – Guide for the Use of the International System of Units](https://www.nist.gov/pml/special-publication-811) - [NIST Handbook 44 Appendix C – General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)