How many mL is 4 fl oz?

4 fluid ounces (fl oz) is equal to approximately 118 milliliters (mL). This conversion can be helpful when cooking, mixing drinks, or any situation where you need to convert between fluid ounce and milliliter measurements.

Quick Answer

4 fl oz = 118 mL

Fluid Ounces to Milliliters Conversion

Fluid ounces and milliliters are both units used to measure liquid volume. Here is some background on each unit:

What is a Fluid Ounce?

A fluid ounce (abbreviated fl oz) is a unit of volume used in the US customary system of measurements. One fluid ounce is defined as exactly 1⁄128 of a US gallon.

Some key facts about fluid ounces:

  • There are 128 fl oz in 1 gallon.
  • There are 8 fluid ounces in 1 cup.
  • A fluid ounce is approximately 29.57 milliliters.
  • Fluid ounces are commonly used to measure volumes of liquids like water, juice, or oil.

What is a Milliliter?

A milliliter (abbreviated mL) is a metric unit used to measure liquid volumes.

Some key facts about milliliters:

  • There are 1000 mL in 1 liter.
  • There are approximately 29.57 milliliters in 1 fluid ounce.
  • Milliliters are commonly used in medicine, chemistry, cooking and other areas.
  • Metric milliliters provide an exact measurement.

As you can see, while both units are used to measure liquid volume, fluid ounces are part of the customary US system while milliliters are part of the modern metric system. Converting between them is common when combining recipes or formulas that use different measurement systems.

Converting 4 fl oz to mL

To convert fluid ounces to milliliters, we need to use a conversion ratio. Since 1 fl oz = 29.57 mL, the conversion ratio is:

1 fl oz = 29.57 mL

We can multiply any fluid ounce measurement by 29.57 to find out how many milliliters it equals.

Let’s convert 4 fl oz to mL using this conversion ratio:

4 fl oz x (29.57 mL / 1 fl oz) = 118.28 mL

Therefore, 4 fl oz equals 118.28 mL when rounded to the nearest hundredth.

For most practical purposes, we can round this to:

4 fl oz = 118 mL

So 4 fluid ounces is equivalent to 118 milliliters.

Converting Milliliters to Fluid Ounces

We can also convert in the opposite direction, from milliliters to fluid ounces.

To do this, we use the same conversion ratio but flipped:

29.57 mL = 1 fl oz

Let’s convert 118 mL to fl oz:

118 mL x (1 fl oz / 29.57 mL) = 4 fl oz

So 118 mL equals 4 fluid ounces.

The conversion works both ways.

Examples of Converting 4 fl oz to mL

Being able to convert between fluid ounces and milliliters is useful any time you need to convert a liquid measurement from US customary units to metric units (or vice versa). Here are some examples:


Many recipes may list liquid ingredients like milk, water, or oil in fluid ounces. If you have metric measuring tools like milliliter cups or spoons, you can easily convert fl oz to mL.

For example, if a recipe calls for 4 fl oz of milk, you now know you can measure out 118 mL instead.

Nutritional Information

Nutrition labels on food and beverages in the US often list serving sizes in fluid ounces. But in many other countries, milliliters are commonly used. Converting fl oz to mL can help compare serving sizes and nutrient information across regions.

For example, if a bottle contains 4 fl oz of juice, it contains 118 mL.

Mixing Drinks

Some cocktail recipes may use fluid ounces to list the different liquor amounts. If you only have metric jiggers or measuring tools, converting to mL makes it easy to follow the recipes.

For instance, if a drink calls for 4 fl oz vodka, use 118 mL of vodka instead.

Other Fluid Ounce to Milliliter Conversions

We can use the same process to convert any number of fluid ounces to milliliters:

  • 1 fl oz = 29.57 mL
  • 2 fl oz = 59.15 mL
  • 3 fl oz = 88.72 mL
  • 5 fl oz = 148 mL
  • 6 fl oz = 177 mL
  • 8 fl oz = 237 mL
  • 16 fl oz = 473 mL

You simply multiply the number of fluid ounces by 29.57 to convert to milliliters.

Here is a handy reference table summarizing some common fluid ounce to milliliter conversions:

Fluid Ounces Milliliters
1 fl oz 29.57 mL
2 fl oz 59.15 mL
4 fl oz 118 mL
8 fl oz 237 mL
16 fl oz 473 mL

How Many Milliliters in Common Fluid Ounce Measurements?

There are a couple other fluid ounce measurements you may encounter when cooking or mixing drinks:

1.5 fl oz

A common measurement for alcohol servings and medicine dosages.

1.5 fl oz = 44 mL

2 fl oz

The typical fluid ounce measurement in many consumer products and bottled goods.

2 fl oz = 59 mL

1.25 fl oz

A common increment on graduated medicine dosing cups.

1.25 fl oz = 37 mL

Knowing these handy conversions allows you to quickly relate common fluid ounce measurements to their approximate milliliter equivalents.

Fluid Ounces to Milliliters Conversion Formula

For those who prefer using formulas, here is the equation for converting fluid ounces (fl oz) to milliliters (mL):

Fluid Ounces x 29.57 = Milliliters

To convert milliliters to fluid ounces, simply reverse the formula:

Milliliters / 29.57 = Fluid Ounces

– Fluid Ounces = fl oz
– Milliliters = mL

So if you know the number of fluid ounces, multiply by 29.57 to get the equivalent number of milliliters.

Or if you know the number of milliliters, divide by 29.57 to get the equivalent fluid ounces.

Converting Between fl oz and mL in Recipes and Measurements

Being able to move between fluid ounce and milliliter measurements is an essential skill for cooks, bakers, nutritionists, chemists, and other fields.

Here are some best practices for converting fluid measurements:

– Keep the full fluid ounce to milliliter conversion ratio handy: 1 fl oz = 29.57 mL

– When converting fluid ounces to milliliters, multiply the fl oz amount by 29.57

– When converting milliliters to fluid ounces, divide the mL amount by 29.57

– Remember that while mL are more precise, fluid ounces are a more familiar frame of reference for volumes used in cooking

– Don’t try to memorize every fl oz to mL conversion. Just remember the base ratio and calculate as needed.

– For convenience, keep a fl oz to mL conversion chart posted in your kitchen or lab for easy reference

– When converting fl oz to mL in recipes: convert every fluid measurement to maintain consistent units

– For the most accuracy, use a digital kitchen scale that can switch between ounce and gram measurements

The History of Fluid Ounces and Milliliters

To understand why we use both fluid ounces and milliliters today, it helps to know a little history:

Fluid Ounces

Fluid ounces have been used as a volume measurement for centuries, dating back at least to Medieval England. The fluid ounce was originally defined as the volume of one ounce of water.

Over time, adjustments were made to standardize the fluid ounce based on more scientific precision. Today in the US, 1 fluid ounce is officially defined as 1/128 of a US gallon.

Fluid ounces are entrenched in many traditional recipes, cooking measurements, nutrition labels, beverage servings, and other consumer product volumes in the US.


The milliliter emerged in the late 18th century during the French Revolution. It was created as part of the metric system, which introduced decimal-based units of measurement.

The milliliter was designed to replace archaic units like teaspoons and provide an exact, standardized volume measurement. The milliliter spread beyond France as the metric system gained wider international adoption throughout the 19th and 20th centuries.

Today, milliliters are the common metric unit used for volumes of liquids and gases worldwide. Milliliters are especially prevalent in healthcare, pharmacy, chemistry, and consumer products in most non-US countries.

The Difference Between Fluid Ounces and Ounces

It’s easy to confuse fluid ounces with ounces, but they are distinct units:

– Ounces (oz) measure weight. There are 16 oz in 1 pound.

– Fluid ounces (fl oz) measure volume. There are 128 fl oz in 1 gallon.

So fluid ounces indicate how much space a liquid takes up, while regular ounces indicate how heavy it is.

For example:

– 8 oz of chicken weighs 8 ounces
– 8 fl oz of water takes up 8 fluid ounces of volume

The volume weight relationship depends on the liquid’s density. For water at room temperature:

– 1 fl oz takes up 1 ounce weight
– But for honey, 1 fl oz weighs about 1.5 oz in weight.

This distinction is important when choosing between fl oz and oz units in cooking, baking, nutrition facts and other uses.

Should I Buy a Fluid Ounce or Milliliter Measuring Cup?

When purchasing measuring cups and other liquid measuring tools, you have a choice between units labeled in:

– Fluid ounces: Typically used for volume measurements in cooking, bartending, and other US applications. Common sizes are 1 fl oz, 2 fl oz, 1 cup (8 fl oz).

– Milliliters: Typically used for precise volume measurements in chemistry, medicine, and baking. Common sizes are 10 mL, 25 mL, 50 mL, 100 mL.

For most home kitchen purposes, a basic set of US customary fluid ounce measuring cups (1 cup, 1⁄2 cup, 1⁄3 cup, 1⁄4 cup) will suffice.

But a separate milliliter measuring cup or syringe is useful for smaller volumes or when greater precision is needed. Some recipes may also specify gram measurements, so a digital kitchen scale with gram/ounce conversion is also handy.

As you become more adept at converting between systems, you’ll feel comfortable working with either fluid ounce or milliliter measurements. But when first starting out, use measuring tools with the units specified in each recipe or formula.

Should the United States Switch to Milliliters?

The United States is one of just a few countries worldwide that still primarily uses US customary units like fluid ounces.

There have been periodic efforts to transition the US to the metric system, including switching volume measurements from fluid ounces to milliliters. However, these have been met with resistance and fluid ounces remain ingrained in American life today.

Here are some pros and cons of switching from fluid ounces to milliliters in the US:


  • Uniformity and precision – Milliliters integrate seamlessly with the decimal-based metric system used worldwide in science, industry, and commerce.
  • Easier conversions – Shifting volumes like lengths and weights to base-10 metric units simplifies conversions.
  • Globalization – Metric volumes enable easier trade and communication with the 95% of the world using the International System of Units (SI).


  • Learning curve – American consumers would have to learn a new unit and measurement system.
  • Cost of changeover – Transitioning all packaging and recipes would take time and money.
  • Loss of traditional volumes – Customary measurements like cups, pints, tablespoons are familiar and tied to culture.

Ultimately, any switch requires public and industry buy-in. But the current blend of both fluid ounce and milliliter labeling on most consumer products enables a gradual learning transition on an optional basis.

Key Takeaways

– 4 fl oz equals approximately 118 mL.
– Fluid ounces measure volume while milliliters are a metric SI volume unit.
– Use the conversion ratio: 1 fl oz = 29.57 mL.
– Converting between fl oz and mL is useful for recipes, measurements, and consumer products.
– Common fl oz amounts like 1.5 fl oz or 2 fl oz can be converted to milliliters.
– Fluid ounces have a long history while milliliters are relatively modern.
– Fluid ounces measure liquid volume while regular ounces measure weight.
– Measuring tools are labeled in both fluid ounces and milliliters.
– The US may eventually switch to milliliters but fluid ounces remain deeply ingrained.

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