When converting milliliters to ounces, 750 ml is the equivalent to roughly 25.4 fluid ounces. Milliliters are part of the metric system, while ounces are part of the US and imperial systems of measurements.
The most popular bottle size for both wine and spirits is 750 ml, although they are also sold in 1 L and 1.5 L sizes. Although the bottles are measured using the metric system, drink recipes usually are created using ounces in the United States. In order to calculate how many drinks a bottle will provide, bartenders need to convert to ounces.
A standard glass of wine contains 5 ounces, so a standard 750 ml bottle provides roughly five glasses of wine. A mixed beverage, like vodka and tonic, normally contains 1.5 ounces of spirits, so a 750 ml bottle contains enough alcohol for roughly 17 drinks.