Quick Answer: Fluid Ounces (US) to Milliliters
One US fluid ounce is approximately 29.57 milliliters (1 fl oz ≈ 29.57 mL).
Conversely, 1 mL ≈ 0.03381 fl oz.
Formula: mL = fl oz × 29.5735295625
Worked examples
- 1 fl oz ≈ 29.57 mL
- 2 fl oz ≈ 59.15 mL
- 4 fl oz ≈ 118.29 mL
Method and limitations
Multiply US fluid ounces by 29.5735295625. The US fluid ounce is 1/128 US gallon, exactly 29.5735295625 mL. A fluid ounce measures volume; it is not the ounce of mass (28.35 g). The imperial fluid ounce is 28.4130625 mL. Calculations use full-precision constants; answers in this box are rounded for readability (≈ marks a rounded value) and the calculator shows up to 9 significant figures. This page uses the US customary fluid ounce (29.5735295625 mL), a unit of volume, not the ounce of mass. The imperial fluid ounce is 28.4130625 mL.
Each factor is exact by definition, derived from exact definitions, or a documented conventional value — see the methodology and sources.
Conversion Formula
Multiply US fluid ounces by 29.5735295625. The US fluid ounce is 1/128 US gallon, exactly 29.5735295625 mL. A fluid ounce measures volume; it is not the ounce of mass (28.35 g). The imperial fluid ounce is 28.4130625 mL.
Complete Guide to Fluid Ounces (US) to Milliliters Conversion
What is a US fluid ounce?
The US fluid ounce (fl oz) is a unit of volume: 1/16 US pint, 2 US tablespoons, exactly 29.5735295625 mL.
What is a milliliter?
The milliliter (mL) is 1/1,000 of a liter, the same as 1 cm³.
How the Conversion Works
mL = US fl oz × 29.5735295625, exact by definition.
Step-by-Step Conversion Guide
Follow these steps to convert fluid ounces (us) to milliliters manually:
Start with your value in fluid ounces (us)
Example: You want to convert 4 fl oz
Apply the conversion formula
Use the formula: mL = fl oz × 29.5735295625
Calculate the result
4 fl oz = 118.2941 mL
Verify your answer
Use our calculator above to double-check your manual calculation.
Quick Mental Math Tip
1 US fl oz ≈ 30 mL is within 1.5%; US nutrition labels use 30 mL.
Common Conversions
| Fluid Ounces (US) (fl oz) | Milliliters (mL) | Milliliters → Fluid Ounces (US) |
|---|---|---|
| 1 fl oz | 29.5735 | 1 mL = 0.033814 fl oz |
| 2 fl oz | 59.1471 | 2 mL = 0.067628 fl oz |
| 4 fl oz | 118.294 | 4 mL = 0.135256 fl oz |
| 6 fl oz | 177.441 | 6 mL = 0.202884 fl oz |
| 8 fl oz | 236.588 | 8 mL = 0.270512 fl oz |
| 12 fl oz | 354.882 | 12 mL = 0.405768 fl oz |
| 16 fl oz | 473.176 | 16 mL = 0.541024 fl oz |
| 20 fl oz | 591.471 | 20 mL = 0.67628 fl oz |
| 32 fl oz | 946.353 | 32 mL = 1.08205 fl oz |
| 64 fl oz | 1,892.71 | 64 mL = 2.1641 fl oz |
Popular Fluid Ounces (US) to Milliliters Conversions
Tap any value to load it into the calculator above.
When You'll Need This Conversion
US-labelled drinks and liquids
Read a 16 US fl oz bottle as 473.18 mL.
Common Mistakes to Avoid
Treating fluid ounces as weight
Only for water near room temperature is 1 US fl oz close to 29.6 g; other liquids differ.
Use mL here and a density for mass.
Frequently Asked Questions
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Conversion factors on this page are either exact by definition, derived from exact definitions, or conventional values in documented use. Each is listed with its source in our conversion methodology and sources, which cites the BIPM SI Brochure, NIST Special Publication 811 and the relevant IEC or national standards. Results are rounded for display only; calculations use full precision.