How to Convert Fluid Ounces to Milliliters

The Fluid Ounces to Milliliters Formula

mL = US Fluid Ounces × 29.5735

mL = Imperial Fluid Ounces × 28.4131

The US and Imperial fluid ounces are different sizes. The US fluid ounce is slightly larger (29.57 mL vs 28.41 mL). For most cooking purposes, rounding to 30 mL per US fluid ounce is practical and easy to remember.

Step-by-Step Examples

Example 1: An 8 fl oz Glass of Water

• Calculation: 8 × 29.5735 = 236.59 mL.
• Result: 8 fl oz = approximately 237 mL (one US cup).

Example 2: A 16.9 fl oz Water Bottle (500 mL)

• Calculation: 16.9 × 29.5735 = 499.79 mL.
• Result: The standard 500 mL water bottle is labeled 16.9 fl oz in the US.

Example 3: A 1.5 fl oz Shot Glass

• Calculation: 1.5 × 29.5735 = 44.36 mL.
• Result: A standard US shot is approximately 44 mL.

Common Volume Reference

Real-World Applications

Beverage Labels

US beverages show fluid ounces while international products show milliliters. Understanding the conversion helps you compare serving sizes and nutritional information across brands from different countries.

Cooking

American recipes use fluid ounces while European recipes use milliliters. A recipe calling for 4 fl oz of cream means approximately 118 mL.

Travel and Airline Regulations

TSA liquid limits are 3.4 fl oz per container (100 mL). International airports use the 100 mL limit directly. Knowing the conversion ensures your travel-size bottles comply with regulations.

Quick Tip

For fast estimates, multiply fluid ounces by 30. This is within 1.4% of the exact value. So 6 fl oz ≈ 180 mL (exact: 177.4 mL). Use our volume converter for precision.