How many cups in 3 grams?

Answer 1

How many cups depends on what substance you are measuring. Cups is a measure of volume, or the space taken up by the substance. Grams, however, is a measure of mass, basically how heavy the substance is. To convert cups to grams, you must first know the density of the substance. Density is mass over volume.

For example, flour has a density of about 125 grams per cup. So 3 grams of flour is equal to: 3 grams flour divided by 125 grams per cup = 0.024 cups, or about 1/45 of a cup, just over a teaspoon of flour. On the other hand, for an even heavier substance, such as oil with a density of 0.9 grams/cm3 (There are 237 cm3 in one cup, so 0.9 grams/cm3 is equal to 0.9 times 237 = 213 grams per cup), 3 grams oil is equal to: 3 grams oil divided by 213 grams per cup = 1/71 cups, or 2/3 tsp of oil. Each substance was 3 grams, but took up different volumes, since their densities were different.

Essentially, substances with lower densities take up more space. This reminds me of an old trick joke, "Which is heavier, a pound of feathers or a pound of rocks?" One might instinctively answer "rocks" because rocks, we all know, are heavier (have higher density) than feathers. A pound, which is a unit of mass (although also takes into account gravity), is a pound regardless of what the density of the substance is. You obviously need many more feathers (a much larger volume) than you need rocks to make up a pound of each.

If you like to cook, learning to interconvert volume to mass is useful. Here in the US, volume is used to specify amounts for both liquids and solids, using gallons, cups, tablespoons, and teaspoons as indicators. In the rest of the world, mass specifies dry substances (using grams or kilograms) and volume specifies liquids (using liters or milliliters).

A simple generic formula for converting mass to volume is this: mass of substance divided by density equals volume.

Example:

(3 grams water) divided by (1 gram water per milliliter (mL) of water) = 3 mL of water.

Then to go from milliliters (mL) to cups: (3 millilters water) divided by (237 mL per cup) = 0.013 cups. Since this is so small, you can change it to tablespoons: 0.013 cups times 16 Tablespoons per cup = 0.20 Tablespoons. This is still small, so change this to teaspoons: 0.20 Tablespoons times 3 teaspoons per tablespoon = 0.6 teaspoons of water. 0.6 is the same as 6/10, which is equal to 3/5. So 3 grams of water is the same as 3/5 teaspoon.