Milliliters to Fluid Ounces Converter
Convert milliliters to US fluid ounces or imperial fluid ounces, and convert either fluid-ounce type back to milliliters. The calculator keeps the two systems separate, applies their exact definitions and shows all three equivalent volumes.
- Three-way conversion
- US and imperial fl oz
- Exact rational engine
- Volume reference tables
Convert mL and Fluid Ounces
Select the fluid-ounce system shown on your source. A US fluid ounce and an imperial fluid ounce have different volumes, so an unqualified fl oz value is not enough for an exact conversion.
Milliliter and fluid-ounce conversion result
100 mL ≈ 3.38140227 US fl oz after display rounding.
Same Volume in All Three Units
| Unit | Symbol | Converted value | Display relation |
|---|
Calculation Steps
How to Use the Milliliters to Fluid Ounces Converter
- Enter the volume. Type a nonnegative decimal or complete scientific-notation value without commas or unit text.
- Choose the source unit. Select milliliters, US fluid ounces or imperial fluid ounces.
- Choose the target unit. Select the volume unit you want. The same-unit choice performs an identity check.
- Set the precision. Choose a displayed limit from 3 to 15 significant digits.
- Convert the volume. Review the main answer, all three equivalent values, the forward factor and the calculation steps.
- Check the fluid-ounce system. Use US fl oz for a US customary measure and imperial fl oz only when the source explicitly uses the imperial system.
Changing any field clears the previous answer. Select Convert Volume to calculate again. Reset returns the calculator to 100 milliliters converted to US fluid ounces. Switch Direction reverses the selected units without changing the entered number. Copy Result copies only the current conversion and its supporting values. Your browser performs the calculation locally.
Milliliters to Fluid Ounces Formulas
The abbreviation fl oz does not identify one universal volume. The correct divisor depends on whether the source uses the US customary fluid ounce or the imperial fluid ounce.
Milliliters to US Fluid Ounces
For the reverse direction, multiply US fluid ounces by exactly 29.5735295625 milliliters per US fluid ounce.
Milliliters to Imperial Fluid Ounces
For the reverse direction, multiply imperial fluid ounces by exactly 28.4130625 milliliters per imperial fluid ounce.
The decimal definitions terminate, but their reciprocals usually do not. A milliliter-to-fluid-ounce answer therefore often needs rounding even though the underlying unit definitions are exact.
Worked mL and Fluid Ounce Examples
Example 1: Convert 100 mL to US fluid ounces
Divide 100 by the exact US factor. The quotient is approximately 3.3814022702, so 100 mL is about 3.38 US fl oz when rounded to three significant digits.
Example 2: Convert 8 US fluid ounces to milliliters
Multiply 8 by 29.5735295625. The exact result is 236.5882365 mL. A product label might show 237 mL after practical rounding.
Example 3: Convert 20 imperial fluid ounces to milliliters
Multiply 20 by 28.4130625. The exact result is 568.26125 mL. Twenty imperial fluid ounces also form one imperial pint.
Example 4: Compare 12 US and imperial fluid ounces
Twelve US fluid ounces equals exactly 354.88235475 mL. Twelve imperial fluid ounces equals exactly 340.95675 mL. The identical number and symbol do not represent the same volume.
Milliliters to Fluid Ounces Conversion Chart
This table shows both fluid-ounce systems. Values are rounded for quick reference. Use the calculator when your source requires a different precision.
| Milliliters | US fluid ounces | Imperial fluid ounces |
|---|---|---|
| 1 mL | 0.033814 US fl oz | 0.0351951 imp fl oz |
| 5 mL | 0.16907 US fl oz | 0.175975 imp fl oz |
| 15 mL | 0.50721 US fl oz | 0.527926 imp fl oz |
| 30 mL | 1.01442 US fl oz | 1.05585 imp fl oz |
| 100 mL | 3.3814 US fl oz | 3.51951 imp fl oz |
| 250 mL | 8.45351 US fl oz | 8.79877 imp fl oz |
| 500 mL | 16.907 US fl oz | 17.5975 imp fl oz |
| 1,000 mL | 33.814 US fl oz | 35.1951 imp fl oz |
Fluid Ounces to Milliliters Quick Chart
| Fluid-ounce value | If US fl oz | If imperial fl oz |
|---|---|---|
| 1 fl oz | 29.5735295625 mL | 28.4130625 mL |
| 2 fl oz | 59.147059125 mL | 56.826125 mL |
| 4 fl oz | 118.29411825 mL | 113.65225 mL |
| 8 fl oz | 236.5882365 mL | 227.3045 mL |
| 12 fl oz | 354.88235475 mL | 340.95675 mL |
| 16 fl oz | 473.176473 mL | 454.609 mL |
| 20 fl oz | 591.47059125 mL | 568.26125 mL |
| 32 fl oz | 946.352946 mL | 909.218 mL |
What Milliliters and Fluid Ounces Measure
A milliliter is a metric unit of volume. One milliliter equals one cubic centimeter, and 1,000 milliliters equal one liter. The preferred symbol is mL, with an uppercase L to reduce confusion between the letter l and the numeral 1.
A fluid ounce also measures volume. It is not the avoirdupois ounce used for food mass, body weight or parcels. The US customary system divides one US liquid gallon into 128 US fluid ounces. The imperial system divides one imperial gallon into 160 imperial fluid ounces.
The physical volume does not depend on the liquid. Ten milliliters of water and ten milliliters of oil occupy the same stated volume, though their masses differ. To convert a liquid volume into grams or ounces by mass, you need its density and should use the Density Calculator.
US Versus Imperial Fluid Ounces
The US customary fluid ounce equals exactly 29.5735295625 mL. It follows from the US liquid gallon of 231 cubic inches, divided into 128 fluid ounces, together with the exact international inch definition. The imperial fluid ounce equals exactly 28.4130625 mL because the imperial gallon is exactly 4.54609 liters and contains 160 imperial fluid ounces.
A US fluid ounce is approximately 1.040842731 times an imperial fluid ounce, so it is about 4.08% larger. The difference becomes more visible as the quantity grows. At 20 fluid ounces, the US interpretation exceeds the imperial interpretation by about 23.21 mL.
Do not infer the system only from the language on a page. Check the country, package, measuring jug or recipe convention. US customary recipes and measures often use the 29.5735295625 mL definition. US nutrition labeling uses a separate legal convention of 30 mL per fluid ounce. Older British and some Commonwealth contexts may use the imperial definition. Metric product labels commonly state mL directly.
Cooking, Product Labels and Medicine
Cooking measures use several conventions. A US customary cup is eight US customary fluid ounces, exactly 236.5882365 mL, and a general conversion may round this to 237 mL. US nutrition labeling instead defines a cup as 240 mL. A metric cup may mean exactly 250 mL. Select the convention actually stated instead of assuming every cup has one size.
Medicine labels may pair milliliters with standardized dosing spoons or cups. Use the supplied device and follow the label or clinician instructions. A household teaspoon is not a reliable measuring instrument. This page performs a unit conversion only and does not determine a dose, frequency or safe quantity.
Cosmetics, drinks and other packaged liquids may show both mL and fl oz. Small differences can reflect legal display rules, permissible label rounding or the fluid-ounce system. Compare values at a sensible precision instead of treating the last printed digit as an independent measurement.
Accuracy, Rounding and Calculator Limits
Both stored fluid-ounce definitions are exact. The calculator parses your decimal as an exact rational number, applies the selected unit ratio with BigInt arithmetic and rounds only the displayed result. It uses round-half-to-even at the chosen significant-digit limit.
An equals sign means the selected display represents the exact rational result. An approximate sign means the display was rounded. This distinction describes the arithmetic display, not the accuracy of your measuring cup, syringe, scale marking or product label.
Zero is valid. Negative values, commas, fractions, unit text, incomplete exponents, Infinity and nonnumeric entries are rejected. Inputs may contain up to 80 significant digits and a scientific exponent from −3000 through 3000. Tiny nonzero values remain nonzero in scientific notation.
Common mL and Fluid Ounce Conversion Mistakes
- Using 30 mL as an exact US customary fluid ounce. It is exact only within the separate US nutrition-label convention.
- Using the US factor for an imperial fluid-ounce value, or the reverse.
- Multiplying milliliters when the formula requires division to get fluid ounces.
- Dividing fluid ounces when the formula requires multiplication to get milliliters.
- Confusing fl oz of volume with oz of mass.
- Assuming every cup, tablespoon or teaspoon follows one international size.
- Rounding the conversion factor before finishing the calculation.
- Reporting more digits than the original measurement supports.
Keep the full exact factor through the calculation, then round the final answer. If the source writes only “fl oz” and gives no country or system, report the ambiguity or calculate both results.
Related Calculators
Measurement notice: This calculator changes volume units. It does not measure a container, convert volume to mass without density, interpret product-label tolerances or provide medical dosing advice.
Milliliters to Fluid Ounces Converter FAQs
How many milliliters are in one US fluid ounce?
One US fluid ounce equals exactly 29.5735295625 milliliters. Multiply US fluid ounces by this factor to get milliliters.
How many US fluid ounces are in 100 milliliters?
One hundred milliliters is approximately 3.381402270 US fluid ounces. The displayed digits should match the accuracy of the original measurement.
How many milliliters are in one imperial fluid ounce?
One imperial fluid ounce equals exactly 28.4130625 milliliters. It is one 160th of the imperial gallon.
Are US and imperial fluid ounces the same?
No. A US fluid ounce is about 4.08 percent larger than an imperial fluid ounce. Select the system stated on the recipe, label or measuring tool.
How do I convert milliliters to fluid ounces?
Divide milliliters by 29.5735295625 for US fluid ounces, or by 28.4130625 for imperial fluid ounces.
How do I convert fluid ounces to milliliters?
Multiply by 29.5735295625 for US fluid ounces, or by 28.4130625 for imperial fluid ounces.
Does fl oz measure weight?
No. A fluid ounce measures volume. An ordinary ounce, symbol oz, measures mass. Converting volume to mass requires the substance density.
Is 30 mL exactly one fluid ounce?
Under the US customary and imperial definitions, no. Thirty milliliters equals about 1.01442 US customary fl oz or 1.05585 imperial fl oz. For US nutrition labeling only, 21 CFR 101.9 defines 1 fl oz as 30 mL.
Why does a medicine label sometimes use 5 mL for one teaspoon?
A 5 mL medicine measure is a standardized metric quantity. Household spoons vary, so use the supplied dosing device and follow the product instructions.
Why is the answer rounded if the unit definitions are exact?
The definitions are exact, but many quotients repeat and real measurements have limited precision. This calculator rounds only the final display to your selected limit.
Method and Review Basis
The conversion model was reviewed against the NIST volume guidance, NIST SP 811 conversion factors, NIST Handbook 44 Appendix C, the UK Units of Measurement Regulations 1995, the BIPM SI Brochure and 21 CFR 101.9 for US nutrition-label household measures. The page stores the exact customary and imperial definitions shown above rather than shortened everyday factors.