This chart will be helpful to you when you need to convert a recipe stated in U.S. cups to metric milliliters. The chart shows the actual conversion number extended to up to 4 decimals as well as rounded to the nearest whole number or nearest 10th. You can choose to use the column that suits the accuracy you need for your particular recipe. As a matter of reference we also include the total tablespoons per cup.
A cup is a U.S. standard volume of measurement used for measuring liquid or dry ingredients. For the discussion of converting cups to ml we are only referring to the use of a standard liquid measuring cup only, not dry measuring cups. Please use the links provided if you are unclear about the difference in the types of measuring cups. A milliliter (ml) is a metric standard volume measurement used to measure liquids. It is equal to one thousandth of a liter.
Some countries use cups that differ in capacity from the U.S. standard, including U.K., Australia and Canada. This chart should be used for U.S. measuring cups only.
National Institute of Standards and Technology - This link is to a PDF prepared by the NIST which shows a few conversions and explains metric principles. This is the U.S. government website.
The Metric Kitchen - A website by JS Ward that explains how to convert from U.S. to metric in great detail. It includes charts, descriptions of measuring tools, basics of the metric system and more. This site is linked to by the NIST. King Aurthur Flour - Offers a good, basic measuring guide. You will see that their small chart of cup/ml conversions have been rounded to the nearest single decimal.
Gourmetsleuth's Grams To Cups Conversion Calculator - Allows you to convert U.S. or U.K. cups to grams, cups, ml, liters, pints, quarts and more. Checkyourmath.com - Offers an excellent set of conversion calculators as well as a wealth of information about metric conversions.
Food Lover's Companion - by Sharon Tyler Herbst The Sunset Cookbook - Over 1,000 Fresh, Flavorful Recipes for the Way You Cook Today. See appendices.
The New Best Recipes - Cooks Illustrated. See conversions on page 1027. A small chart is provided with conversions rounded to the nearest whole number.
Milliliters are typically measured in glass or plastic liquid measuring cups. The cups show U.S. liquid ounces as well as milliliters. An old U.S. standard measuring cup is made by PYREX. These measuring cups are typically graduated in 25ml increments.
As an example; if you look at the chart you'll see that 2 cups is equal to about 475ml (rounded to the nearest 10th). If you look at a glass measuring cup, you'll see something like the image below. You can see that 2 cups is about equal to the 475ml mark and that 500ml is actually about 2 1/8 cups. When measuring liquids you should always hold the measuring up to your eye level, keeping the vessel level. You can see that volume measuring is inherently inaccurate. You can purchase beaker style measuring vessels with smaller than 25ml increments which is helpful when more accuracy is needed. When measuring liquids less than 1/4 cup, it is typically done using measuring spoons.
After much research we have found there is no clear, definitive guide or standards for the presentation of of U.S. cups to milliliters conversions. The few charts that exist which are published by the U.S. government provide conflicting information. The same is true for most of the charts we found on high-ranking, authoritative websites. To clarify, none of the charts are inaccurate, there is a specific formula to do the conversion (mL = US cup x 236.58823649999998976).
The fact is that different sites and references simply round the converted numbers differently. Some sites state 1 cup = 240ml while others state it's 236ml and some say it is 250ml. For the purposes of this chart we have provided you with each measurement rounded to the nearest 10th as well as rounded to the nearest whole number. Both of these conversions are sufficiently accurate for most recipes. We also provide the accurate conversion amount carried out to up to 4 decimal places so you can get as accurate as you may need.
NOTE: Given most common measuring cups are graduated in 25ml increments, it will be a guessing game trying to measure increments that fall between those increments. (for example) 234ml, 210ml, etc.
We don't sell this type of product but you can find a large selection of Beakers and Measuring Utensils at Amazon.com.