1 gram is how many milliliters?

Answer 1

You cannot directly convert milliliters into grams. A milliliter is to measure the volume of something. A gram is to measure the weight of something. But to give you an idea, 1 milliliter of water (H2O) weighs 1 gram.

Answer 2

A gram is a measure of mass. A millilitre is a measure of volume. The two measure different things and, according to basic principles of dimensional analysis, conversion from one to the other is not valid.

Some people still believe that there is a conversion in relation to water but that is only approximately true. Until 1964 (MORE THAN 50 YEARS AGO!) a litre was defined as the volume of one kilogram of pure water at 4 degrees Celsius and at a pressure of 760 millilitres of Mercury. With that definition a conversion would have been valid - but only for pure water and only under those conditions. In any case that definition of a litre was abandoned in favour of 1 litre =1000 cubic centimetres.

The current definition gives the density of pure water under those conditions as 999.9720 kg/metre3, not 1000.