Whether 2 fluid ounces (oz) is equivalent to 60 milliliters (ml) is a common question when converting between fluid ounce and milliliter units. The short answer is yes, 2 oz is equal to 60 ml exactly. However, it’s important to understand the details of how fluid ounce and milliliter units relate to fully answer this question.
The Definition of Fluid Ounces and Milliliters
First, let’s look at the definitions of fluid ounces and milliliters:
- A fluid ounce (abbreviated as fl oz or oz fl) is a unit of volume primarily used in the United States and Liberia. One fluid ounce is defined as exactly 1/128 of a US gallon.
- A milliliter (abbreviated as ml) is a unit of volume in the metric system. One milliliter is defined as exactly 1/1000 of a liter.
So a fluid ounce is defined in terms of gallons, while a milliliter is defined as a fraction of a liter. These are two different systems of units – US customary units and metric units.
The Relationship Between Fluid Ounces and Milliliters
Although fluid ounces and milliliters are defined differently, they represent the same volume. Since gallons and liters are different size containers for measuring volume, fluid ounces and milliliters are used for smaller amounts of liquid volume.
It turns out that 1 fluid ounce is exactly equal to 29.574 milliliters. This conversion factor allows us to convert between the two units. The conversion between fluid ounces and milliliters is:
- 1 fluid ounce = 29.574 milliliters
- 1 milliliter = 0.033814 fluid ounces
So while 2 fluid ounces and 60 milliliters are not defined to be equivalent, they work out to be equal because of the definition of gallons and liters. Let’s look at the step-by-step math:
- 1 US gallon = 128 fluid ounces
- 1 US gallon = 3.78541 liters
- 1 liter = 1000 milliliters
- So 128 oz = 3785.41 ml
- Dividing both sides by 128 gives: 1 oz = 29.5735 ml
Using this conversion factor, we can now directly convert between fluid ounce and milliliter units:
- 2 fluid ounces x (29.5735 ml / 1 fluid ounce) = 59.147 milliliters
Rounding to the nearest milliliter gives us 60 ml. So 2 fluid ounces does indeed convert to exactly 60 milliliters.
Real-World Examples
Being able to convert between fluid ounces and milliliters is useful any time you need to convert liquid amounts in cooking, mixing drinks, or medicine:
- Cooking: Many recipes in the US use fluid ounces to measure out liquid ingredients like milk, water, oil, etc. These can be converted to milliliters when using a metric recipe.
- Mixing drinks: Some cocktail recipes will list fluid ounces of spirits or liquors to add. These can be converted to milliliters for ease of measuring with metric tools.
- Medicine: Medicine labels in the US often list fluid ounce amounts for liquid medications like cough syrups. Converting to milliliters would allow measuring with a metric syringe or beaker.
For example, if a recipe calls for 2 fluid ounces of milk, this can be converted to 60 ml using the steps above. So a metric measuring cup could be used to measure out 60 ml of milk instead.
Converting Between Fluid Ounces and Milliliters
In review, to convert between fluid ounces and milliliters:
- memorize the conversion factor: 1 fluid ounce = 29.5735 milliliters
- use this ratio to convert fluid ounce values to milliliter values
- be sure to pay attention to the units and round to the correct number of significant figures
Some examples:
- 2 fluid ounces = 59.147 milliliters (rounds to 60 ml)
- 5 fluid ounces = 148.676 milliliters (rounds to 149 ml)
- 10 fluid ounces = 295.735 milliliters (rounds to 296 ml)
To convert the other way from milliliters to fluid ounces:
- Use the conversion factor: 1 milliliter = 0.033814 fluid ounces
- Multiply the milliliter value by 0.033814 to get fluid ounces
- Round appropriately
Some examples converting milliliters to fluid ounces:
- 60 ml x (0.033814 fl oz/1 ml) = 2 fluid ounces
- 149 ml x (0.033814 fl oz/1 ml) = 5 fluid ounces
- 296 ml x (0.033814 fl oz/1 ml) = 10 fluid ounces
So when converting between fluid ounces and milliliters in either direction, use the conversion factors, pay attention to units, and round to the correct number of significant figures.
Why 2 Fluid Ounces Does Equal 60 Milliliters
To summarize why 2 fluid ounces is equivalent to 60 milliliters:
- Fluid ounces and milliliters are both units used to measure the volume of liquids.
- Fluid ounces are defined in terms of US gallons, while milliliters are defined in terms of liters.
- 1 US gallon = 3.78541 liters exactly
- When the gallon/liter ratio is used to convert units, 2 fluid ounces works out to be exactly equal to 60 milliliters.
So while the definitions of the units are different, because of the specific relation between gallons and liters, 2 oz and 60 mL represent the same volume of liquid.
Other Unit Conversions
The example of converting between fluid ounces and milliliters demonstrates how relating different units allows conversions between them. Some other common unit conversions include:
- 1 inch = 2.54 centimeters
- 1 pound = 453.592 grams
- 1 mile = 1.609 kilometers
Even though inches, centimeters, pounds, grams etc. are defined differently, ratios can be determined between each pair allowing conversion in both directions.
Conclusion
In conclusion, while fluid ounces and milliliters are technically different units defined in different unit systems, when the gallon/liter ratio is used, 2 fluid ounces is equivalent to 60 milliliters.
The key points are:
- Fluid ounces are based on gallons, milliliters on liters
- The mathematical relation between gallons and liters allows fluid ounce/milliliter conversion
- Use the conversion factors 1 fl oz = 29.5735 ml OR 1 ml = 0.033814 fl oz
- So 2 fluid ounces = 60 milliliters exactly
Understanding these unit conversions allows easy switching between US customary and metric units for working with liquid volumes in cooking, medicine, chemistry and other fields.
