The molecular weight of glucose is 180 grams per mole, which is based on its empiric formula of C6 H12 O6. This is calculated by adding the weights of each of the elements.
Each carbon has a molecular weight of 12. Since glucose has 6 carbons, 12 multiples by 6 equals 72 grams per mole. Each hydrogen is approximately 1, which contributes another 12 grams per mole. Each oxygen is 16, so 16 multiplies by 6 gives 96 grams per mole. The sum of 72, 12 and 96 is 180. Sugars containing 6 carbons, such as glucose, galactose and fructose, are collectively referred to as hexoses.