Unit converter
US Fluid Ounces to Milliliters Converter
Change US fluid ounces into millilitres for recipes, doses, and labels that cross the Atlantic. The exact factor is 1 US fl oz = 29.5735295625 ml, taken from the US customary gallon and the litre definition used by the conversion engine. This page is for the US fluid ounce, the one seen on American soft drink cans, cocktail measures, medicine cups, and imported product labels. It is not the imperial fluid ounce used with older British measures, so the number is different from UK pub and household references.
1 US fluid ounce = 29.5735 milliliters
Common US fluid ounces to milliliters values
| US fluid ounces | Milliliters |
|---|---|
| 1 fl oz | 29.5735 ml |
| 2 fl oz | 59.1471 ml |
| 5 fl oz | 147.87 ml |
| 10 fl oz | 295.74 ml |
| 20 fl oz | 591.47 ml |
| 50 fl oz | 1,478.68 ml |
| 100 fl oz | 2,957.35 ml |
How to convert
- Start with the volume in US fluid ounces, checking that the label or recipe really says US fl oz.
- Multiply by 29.5735295625 to convert the US customary volume into millilitres.
- Keep the full decimal result while measuring medicine, bitters, syrups, or small cocktail additions.
- Round to sensible kitchen precision only after the multiplication, for example to the nearest millilitre for a jug.
- For a quick head check, treat each US fl oz as about 30 ml, then subtract roughly 1.4 percent from the rough answer.
millilitres = US fluid ounces * 29.5735295625
The conversion uses the US fluid ounce volume expressed in litres, then divides by the millilitre size. Multiplying the US fl oz amount by 29.5735295625 gives the corresponding millilitres. The reverse operation divides millilitres by the same factor.
- US fl oz
- the starting volume in US fluid ounces
- 29.5735295625
- millilitres in one US fluid ounce
Worked example
A 1.5 US fl oz cocktail pour is 1.5 multiplied by 29.5735295625, giving 44.36029434375 ml. On a bar measure you would normally read that as about 44.36 ml, or 44 ml when the recipe does not need fine laboratory precision.
Key facts
- US drink cans often quote 12 US fl oz, which is 354.88235475 ml.
- A US jigger of 1.5 fl oz converts to 44.36029434375 ml.
- US nutrition labels and medicine cups use this unit, not the imperial fluid ounce.
- One US gallon contains 128 US fluid ounces, which is why the US fl oz is smaller than a US cup by a factor of eight.
Tips
- Look for "US" or American packaging context before using this page for a fluid ounce value.
- Use a metric syringe or measuring cylinder for medicine rather than estimating from a spoon.
- When scaling cocktails, convert every liquid to millilitres first, then add the metric amounts.
Frequently asked questions
How many millilitres in 1 US fluid ounce?+
There are exactly 29.5735295625 ml in 1 US fl oz using the factor in this calculator.
Is a US fluid ounce the same as a British fluid ounce?+
No. A US fluid ounce is about 29.57 ml, while an imperial fluid ounce is about 28.41 ml. The names look close, but the gallons behind them are different.
Can I use 30 ml for cocktail recipes?+
For casual mixing, 30 ml is a workable mental estimate for 1 US fl oz. For a scaled batch or a labelled ingredient statement, use 29.5735295625 ml before rounding.
Why do medicine labels show ml and fl oz together?+
US medicine packaging often uses both systems so a dosing cup can match the legal label and a metric syringe. Convert carefully because small dose errors matter more than drink recipe errors.
Things to watch
- Rounding 1 US fl oz to 30 ml is convenient, but the error grows in batch recipes and concentrated syrups.
- Do not mix US fluid ounces with imperial fluid ounces; they differ by a little over 4 percent.
Sources
- NIST Guide for the Use of the International System of Units, SP 811 · NIST
- The International System of Units (SI Brochure) · BIPM
Last updated: 2026-01-01
Conversions use internationally defined factors. Provided for general use; verify critical measurements independently.