oz to ml and ml to oz converter (fluid ounces)
oz to ml for liquids: 1 US fluid ounce is 29.5735 mL, so a cup of 8 oz = 236.59 mL. Enter ounces and see milliliters while you type – or enter milliliters to get ounces. The UK ounce is smaller (28.4131 mL) and shown below the answer.
Example: Volume 8 · Direction: oz to ml (US fl oz → mL) → Answer: 8 fl oz = 236.59 mL. Source: NIST SP 811, Appendix B.8 – gallon (US) = 231 in³ = 3.785411784 L (exact); fluid ounce (US) = 1/128 gallon = 29.5735295625 mL. Updated: .
How it is calculated
How to convert oz to ml
milliliters = US fluid ounces × 29.5735295625. For a 12 oz can: 12 × 29.5735295625 = 354.88 mL (the label says 355 mL). Going back, fluid ounces = milliliters ÷ 29.5735295625: 500 mL ÷ 29.5735 = 16.91 fl oz, which is why bottled water is sold as 16.9 oz. The factor is exact: a US gallon is 231 cubic inches or 3.785411784 L, and an ounce is 1/128 of it.
US ounce or UK ounce?
The US fluid ounce is 29.5735 mL; the imperial (UK) fluid ounce is 28.4131 mL (exactly 28.4130625 mL), about 4 % smaller. The gap grows with the unit: a US pint has 16 oz = 473.18 mL, a UK pint has 20 oz = 568.26 mL. A recipe from a British source may use the imperial ounce. The line under the answer shows what your number would be in UK ounces: 8 oz is 227.3 mL read as imperial.
Fluid ounces are not weight ounces
An ounce of weight is 28.349523125 g and measures mass, a fluid ounce measures volume. Only for water do they come close: 1 US fl oz of water weighs about 29.57 g, or 1.043 oz of weight. Honey, oil and flour weigh differently, so do not convert dry ounces with this page; use the weight converter for those.
Cups and tablespoons
One US cup is 8 fl oz = 236.59 mL and one US tablespoon is 0.5 fl oz = 14.79 mL, so 16 tablespoons make a cup. US nutrition labels round a cup to 240 mL, which is why a label serving can differ from your measuring cup by 3.4 mL.
A quick mental trick
Multiply ounces by 30: 6 oz is about 180 mL (exact: 177.44 mL). To go back divide milliliters by 30: 250 mL ≈ 8.3 oz (exact: 8.45 oz). The error is about 1.4 %, fine for drinks, but measure medicine with a dosing syringe, not by this shortcut.
For liters and gallons see liters to gallons or the cups to grams converter for baking.
Frequently asked questions
How many ml is 1 oz?
1 US fluid ounce is 29.5735 mL (1 UK fluid ounce is 28.4131 mL). 2 oz is 59.15 mL and 8 oz is 236.59 mL.
How do I convert oz to ml?
Multiply the fluid ounces by 29.5735. Example: 12 oz × 29.5735 = 354.88 mL.
How many ounces is 100 ml?
100 mL is 3.38 US fluid ounces. In UK ounces it is 3.52.
How many ml is a 16.9 oz water bottle?
16.9 US fl oz is 499.79 mL, which is the 500 mL on the label.
Is an ounce of liquid the same as an ounce of weight?
No. A fluid ounce is a volume (29.5735 mL), an ounce of weight is a mass (28.3495 g). They match only roughly for water.
Sources and legal basis
- NIST SP 811, Appendix B.8 – gallon (US) = 231 in³ = 3.785411784 L (exact); fluid ounce (US) = 1/128 gallon = 29.5735295625 mL
- UK Weights and Measures Act 1985, Schedule 1 – imperial gallon = 4.54609 L, fluid ounce = 1/160 gallon
As of: · Editorial policy
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