How many cups is 30 grams?
Cups are used to express a volume and grams are used to express
Therefore grams and cups aren't compatible.
If you need 30g of water however you need 0.127 cups
since 1 cup is 236.6 ml (0.127 = 30/236.6)). This is because the
density of water is 1 g/ml.
Another substance will give a different result though.
It depends what substance you are trying to measure, as grams are a
measure of weight, while cups measure volume. Different substances
have different weights relative to their volumes. For example, 30
grams of lead would take up far less volume than 30 grams of
feathers, as lead is much more dense than feathers are.