How to convert fluid ounces to milliliters
To convert fluid ounces to metric milliliters, multiply your fluid ounce value by the volume factor for your region:
Milliliters (US Customary) = US fl oz × 29.57353 Milliliters (UK / Imperial) = UK fl oz × 28.41306 Example: 8 US fl oz (1 Standard US Cup) 8 × 29.5735 = 236.59 ml Quick mental math shortcut for kitchen baking
For everyday cooking, most chefs round 1 US fl oz to 30 ml. Multiply the ounce value by 30, then subtract 1 ml for every 10 fl oz to keep it accurate.
US Customary vs. Imperial (UK) fluid ounces
A common cause of recipe failures is confusing US and Imperial fluid ounces:
- US Customary Fluid Ounce: Equal to 29.57 ml. Used across the United States for food, beverages, and cooking metrics.
- Imperial (UK) Fluid Ounce: Equal to 28.41 ml. Used historically across the UK, Ireland, Canada, and Australia.
An Imperial fluid ounce is roughly 4% smaller than a US fluid ounce. When scaling large beverage batches, this difference adds up quickly.
Common water bottle & beverage volume chart
Drinkware, standard water bottles, and cocktail jiggers rely on fixed fluid-ounce sizes. Here is how standard commercial capacities translate to milliliters:
| Fluid Ounces (fl oz) | US Equivalent (ml) | UK/Imperial Equivalent (ml) | Common Context / Container Size |
|---|---|---|---|
| 1.5 fl oz | 44.36 ml | 42.62 ml | Standard US bar shot / jigger |
| 8 fl oz | 236.59 ml | 227.30 ml | 1 US Cup / Standard beverage mug |
| 12 fl oz | 354.88 ml | 340.96 ml | Standard soda can / beer bottle |
| 16.9 fl oz | 500.00 ml | 480.18 ml | Standard 0.5 Liter plastic water bottle |
| 20 fl oz | 591.47 ml | 568.26 ml | 1 British Imperial Pint (20 UK oz) |
| 24 fl oz | 709.76 ml | 681.91 ml | Medium sports water bottle |
| 32 fl oz | 946.35 ml | 909.22 ml | 1 US Quart / Large Nalgene water bottle |
| 128 fl oz | 3,785.41 ml | 3,636.87 ml | 1 US Gallon water jug |
Need to convert the other way? Use our mL to Oz Converter or check our full Cooking Converter.
Frequently asked questions
How many ml is 1 fluid ounce?
One US fluid ounce equals 29.57 ml, while one UK Imperial fluid ounce equals 28.41 ml. In everyday cooking, 1 fl oz is often rounded to 30 ml.
How many ml is in a 16.9 oz water bottle?
A 16.9 fl oz water bottle contains exactly 500 milliliters (0.5 liters).
Is fluid ounces (fl oz) the same as weight ounces (oz)?
No. Fluid ounces measure liquid volume, whereas standard ounces measure weight or mass. They are only equal when measuring pure water (1 US fl oz of water weighs approximately 1.04 oz).
How many ml is 8 oz of milk or water?
8 US fluid ounces of water or milk equals 236.59 ml. Because fluid ounces measure volume, the liquid type does not change the ml volume calculation.