Everyday situations often require you to convert given units of mass -- for example, grams, kilograms or ounces -- to units of volume, such as fluid ounces, milliliters or cups. Converting from grams to cups requires knowledge of the substance's density and the ability to translate between metric and U.S. standard units.
From Mass to Volume
The first step in the conversion of grams to cups is translating mass to volume within the metric system. To do this, you must know the density of your substance -- its mass divided by its volume. Refer to a list for this. For example, if you have 1,000 grams of titanium, which has a density of 4.5 grams per cubic centimeter, your sample must occupy (1,000 g)(4.5 g/cc) = 222.2 cc, which is the same as 222.2 milliliters.
From Milliliters to Cups
Now that you know how many milliliters of your substance you have, simply multiple this by 0.0042268 to determine how many cups of it you have. 222.2 milliliters of titanium, then, equals 0.0042268 * 222.2 cups or about 15/16 of a cup.