Molar MassMolar mass of glucose (C6H12O6)
The molar mass of glucose, C6H12O6, is 180.16 g/mol. One mole of it, which is 6.022 × 1023 molecules, has a mass of 180.16 grams.
180.16 g/mol
6 × 12.011 + 12 × 1.0080 + 6 × 15.999 = 180.156 · 24 atoms in the formula · also called dextrose, grape sugar
About glucose
Glucose is the sugar that plants make in photosynthesis and that cells burn for energy. Its empirical formula is CH2O, and the molecular formula is six times that. Fructose has the same formula and therefore the same molar mass.
Other names: dextrose, grape sugar.
The working
The formula C6H12O6 has 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms, 24 atoms in all. Multiply each count by the atomic weight of the element and add:
| Element | Atoms | Atomic weight | Total | Share by mass |
|---|---|---|---|---|
| Carbon (C) | 6 | 12.011 | 72.066 | 40.00% |
| Hydrogen (H) | 12 | 1.0080 | 12.096 | 6.71% |
| Oxygen (O) | 6 | 15.999 | 95.994 | 53.28% |
6 × 12.011 + 12 × 1.0080 + 6 × 15.999 = 180.156 g/mol
With the rounded atomic masses used in many school books (C = 12, H = 1, O = 16) the answer is 180 g/mol. The difference from 180.16 is too small to matter in most school sums.
Percentage composition
By mass, C6H12O6 is 40.00% carbon, 6.71% hydrogen and 53.28% oxygen. The largest share comes from oxygen. In a 100 g sample there are 40.0 g of carbon, 6.7 g of hydrogen and 53.3 g of oxygen.
Notice that hydrogen has more atoms in the formula (12) than oxygen (6), yet gives a smaller share of the mass. Percentage by mass depends on how heavy each atom is, not only on how many there are.
Worked examples
Grams to moles. How many moles are in 25 g of C6H12O6? Divide the mass by the molar mass: 25 ÷ 180.16 = 0.1388 mol.
Moles to grams. What is the mass of 0.1 mol of C6H12O6? Multiply: 0.1 × 180.16 = 18.02 g.
Counting particles. 25 g contains 0.1388 mol × 6.022 × 1023 = 8.357 × 1022 molecules, and 2.006 × 1024 atoms in all.
Quick conversion tables
| Amount | Mass |
|---|---|
| 0.1 mol | 18.02 g |
| 0.5 mol | 90.08 g |
| 1 mol | 180.2 g |
| 2 mol | 360.3 g |
| 5 mol | 900.8 g |
| Mass | Moles |
|---|---|
| 1 g | 0.005551 mol |
| 10 g | 0.05551 mol |
| 100 g | 0.5551 mol |
| 1 kg | 5.551 mol |
For other amounts use the grams and moles converter.
Questions people ask
What is the molar mass of C6H12O6?
The molar mass of glucose (C6H12O6) is 180.16 g/mol, or 180.156 g/mol before rounding, using IUPAC abridged atomic weights.
How many moles are in 100 g of C6H12O6?
100 ÷ 180.16 = 0.5551 mol.
What is the mass of one molecule of C6H12O6?
Divide the molar mass by the Avogadro constant: 180.16 ÷ 6.022 × 1023 = 2.992 × 10-22 g.
What is the percentage of oxygen in C6H12O6?
Oxygen makes up 53.28% of the mass of C6H12O6: 6 × 15.999 ÷ 180.156 × 100.
Which values? This site uses the abridged standard atomic weights published by IUPAC (CIAAW), read on 12 November 2026. Your textbook or question paper may round them differently, for example H = 1 and O = 16, so its answer can differ slightly. In an exam, use the values the paper gives.