Fluid Ounces to Milliliters Guide: Conversion Formula & Charts
Quick Answer
- *1 US fl oz = 29.5735 mL. For quick math, multiply oz by 30.
- *1 UK fl oz = 28.4131 mL. The US ounce is ~4% larger than imperial.
- *Fluid ounces measure volume, not weight. They’re different units.
- *Common: 8 oz = 237 mL (1 cup), 12 oz = 355 mL (soda can), 16 oz = 473 mL (pint).
The Conversion Formula
The relationship between fluid ounces and milliliters depends on which fluid ounce you mean. The US and UK definitions differ, and confusing them can throw off recipes, medications, and chemical measurements.
US fluid ounce: 1 fl oz = 29.5735 mL
UK (imperial) fluid ounce: 1 fl oz = 28.4131 mL
The difference traces back to how each system defines a gallon. The US gallon is 231 cubic inches (3,785 mL); the imperial gallon is based on 10 pounds of water (4,546 mL). Divide each by 128 and 160 respectively and you get different fluid ounce sizes.
Quick Reference Chart (US Fluid Ounces)
| Fluid Ounces | Milliliters | Common Use |
|---|---|---|
| 1 fl oz | 29.6 mL | Shot (small) |
| 1.5 fl oz | 44.4 mL | Standard shot |
| 2 fl oz | 59.1 mL | Espresso double shot |
| 4 fl oz | 118.3 mL | Small juice glass |
| 8 fl oz | 236.6 mL | 1 US cup |
| 12 fl oz | 354.9 mL | Soda can |
| 16 fl oz | 473.2 mL | US pint |
| 32 fl oz | 946.4 mL | US quart |
| 128 fl oz | 3,785.4 mL | US gallon |
US vs. UK Fluid Ounces: Why It Matters
A US pint contains 16 fluid ounces (473 mL). A UK pint contains 20 fluid ounces (568 mL). Order a pint of beer in London and you get about 20% more than in New York. This difference catches tourists off guard.
Recipes from the UK, Australia, and New Zealand may use imperial measurements. If a British recipe calls for 10 fl oz, that’s 284 mL, not 296 mL. For baking, where precision matters, this 4% difference can affect the result.
Fluid Ounces vs. Weight Ounces
This trips up almost everyone at some point. “Ounces” can mean volume (fluid ounces, fl oz) or weight (avoirdupois ounces, oz). One fluid ounce of water happens to weigh almost exactly one ounce — but that’s a coincidence specific to water.
Honey is about 1.4 times denser than water, so 1 fl oz of honey weighs about 1.5 oz. Olive oil is lighter: 1 fl oz weighs about 0.95 oz. When a recipe says “4 oz of flour,” they mean weight. When it says “4 fl oz of milk,” they mean volume. Confusing them changes the recipe entirely.
Kitchen Measurement Conversions
| Measurement | Fluid Ounces | Milliliters |
|---|---|---|
| 1 teaspoon | ~0.17 fl oz | 4.93 mL |
| 1 tablespoon | 0.5 fl oz | 14.79 mL |
| ¼ cup | 2 fl oz | 59.1 mL |
| ⅓ cup | 2.67 fl oz | 78.9 mL |
| ½ cup | 4 fl oz | 118.3 mL |
| 1 cup | 8 fl oz | 236.6 mL |
Beverage Bottle Sizes
Drink packaging mixes metric and imperial units depending on the market. A “2-liter” soda bottle is 67.6 fl oz. A “20 oz” sports drink is 591 mL. Wine bottles worldwide are standardized at 750 mL (25.4 fl oz). Mini bottles on airplanes are typically 187 mL (6.3 fl oz).
Energy drinks often come in 250 mL (8.45 fl oz) cans in Europe and 8.4 fl oz (248 mL) in the US. The difference is negligible, but it shows how packaging adapts to local measurement preferences.
Convert fluid ounces and milliliters instantly
Use our free Oz to mL Converter →Frequently Asked Questions
How many milliliters are in 1 fluid ounce?
One US fluid ounce equals 29.5735 mL. One UK (imperial) fluid ounce equals 28.4131 mL. The US fluid ounce is about 4% larger. Most online recipes use US fluid ounces unless specified.
What is the difference between US and UK fluid ounces?
A US fluid ounce is 29.5735 mL while a UK imperial fluid ounce is 28.4131 mL. This means a US pint (16 oz) is 473 mL but a UK pint (20 oz) is 568 mL.
How do I convert ounces to milliliters for cooking?
Multiply fluid ounces by 29.574 (or round to 30 for easy math). A recipe calling for 8 fl oz of milk needs about 237 mL. One US cup equals 8 fl oz or 236.6 mL.
Are fluid ounces the same as weight ounces?
No. Fluid ounces measure volume, while ounces measure weight. One fluid ounce of water weighs approximately one ounce, but this only works for water. Denser liquids like honey weigh more per fluid ounce.
How many mL are in common drink sizes?
A standard US soda can is 12 fl oz (355 mL). A US pint glass is 16 fl oz (473 mL). A wine bottle is 750 mL (25.4 fl oz). A standard shot is 1.5 fl oz (44 mL).