Fluid Ounce to Milliliter Converter

Understanding the Units

Fluid ounces and milliliters represent two different measurement systems used around the world:

Fluid Ounce (fl oz)

The fluid ounce belongs to the imperial and US customary measurement systems. It's important to note there are two types:

• US Fluid Ounce:Equal to 1/128 of a US gallon or 29.5735 milliliters
• UK/Imperial Fluid Ounce:Equal to 1/160 of an imperial gallon or 28.4131 milliliters

The US fluid ounce is most commonly used in the United States and is the standard for food labeling, recipes, and beverages in the US.

Milliliter (mL)

The milliliter is a unit of volume in the metric system, which is used by most countries worldwide. One milliliter equals:

• 1/1000 of a liter
• 1 cubic centimeter (cm³)
• Approximately 0.033814 US fluid ounces

Historical Background

The history of these measurements reveals why we have different systems today:

• The fluid ounce originated from the Roman "uncia" (ounce) and evolved over centuries
• The US fluid ounce was based on the wine gallon used in England before 1824
• After 1959, the US fluid ounce became standardized to exactly 29.5735295625 mL
• The milliliter was introduced during the French Revolution as part of the metric system, designed to provide uniformity and ease of conversion

Conversion Formula

To convert fluid ounces to milliliters, use this formula:

For the reverse conversion:

Practical Applications

Cooking and Baking

Understanding this conversion is crucial when following recipes from different countries:

• American recipes typically use fluid ounces
• European and international recipes often use milliliters
• Common cooking measurements: 8 fl oz (1 cup) = 236.588 mL

Beverages

Beverage containers often use both measurements for international markets:

• Standard water bottle: 16.9 fl oz = 500 mL
• Typical can of soda: 12 fl oz = 355 mL
• Wine bottle: 25.4 fl oz = 750 mL

Medicine and Science

Precise measurements are critical in healthcare and laboratory settings:

• Medicine dosages are typically in milliliters for precision
• Scientific experiments use the metric system (milliliters) for universal standardization
• Over-the-counter medications may display both units for convenience

Conversion Accuracy

When making conversions, be aware of:

• The US fluid ounce (29.5735 mL) vs. the UK fluid ounce (28.4131 mL)
• For nutrition labeling in the US, the FDA rounds to 30 mL per fluid ounce
• Scientific and medical applications require more precise conversions
• For everyday cooking, slight rounding is usually acceptable

Volume Conversion Table

Tips for Accurate Conversions

• Always check whether you're working with US or UK fluid ounces
• Use a digital scale for the most accurate measurements in cooking
• For medical purposes, always use calibrated measuring tools
• When in doubt, check the conversion calculation twice
• Use online converters or smartphone apps for quick conversions

Note: This guide focuses on US fluid ounces. For UK/Imperial fluid ounces, multiply by 28.4131 instead of 29.5735.