# fluid ounce

CEFR B2 · Noun

Source: https://englishreference.com/word/fluid-ounce
Updated: 2026-08-05

## Definition

a small unit for measuring liquids, mostly used in the US. There are about 30 milliliters in one fluid ounce.

For teachers: a unit of liquid capacity equal to one-sixteenth of a US pint or one-twentieth of an imperial pint. Often abbreviated as 'fl oz'.

## Examples

- The bottle contains eight fluid ounces of juice.
- The recipe calls for four fluid ounces of milk, which is roughly half a cup in US cooking measurements.
- Standardization of product labeling requires manufacturers to list both fluid ounces and milliliters to ensure the volume is understood by consumers using different systems of measurement.

## Usage notes

- Typically abbreviated as 'fl. oz.' in both American and British English; note that the US and imperial volumes differ slightly.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.