Molar mass of glucose (C₆H₁₂O₆)
Glucose has a molar mass of 180.16 g/mol, from six carbons, twelve hydrogens and six oxygens. The same formula also describes fructose and galactose, which is a good reminder that a molecular formula does not fix a substance.
Updated on October 7, 2026
Formula, molar mass and composition
C₆H₁₂O₆
180.156 g/mol± 0.0135
- Formula
- C₆H₁₂O₆
- IUPAC
- D-glucose
- Name
- glucose
- Molar mass
- 180.156 g/mol
Composition by mass
| Symbol | Name | Atoms | Standard atomic weight | Share of mass |
|---|---|---|---|---|
| C | Carbon | 6 | 12.011 | 40.00 % |
| H | Hydrogen | 12 | 1.008 | 6.71 % |
| O | Oxygen | 6 | 15.999 | 53.28 % |
IUPAC publishes a range for this element because its isotopic composition varies in nature. The value shown is the conventional atomic weight, and the uncertainty is half the width of that range, not a measurement error.
Same formula, different sugars
Fructose and galactose are also C₆H₁₂O₆, with the same 180.16 g/mol. They differ in how the atoms are connected and arranged in space, which is enough to change how sweet they taste and how your body handles them. To name one specific molecule you need more than the formula, which is why the IUPAC name of blood sugar is D-glucose.
A 5% glucose drip, 5 g in 100 ml, is 0.0278 mol in 100 ml, that is 278 mmol/l. Hospital figures for blood glucose are quoted in mmol/l in much of the world and in mg/dl in the United States and Brazil; the conversion runs through this same molar mass, 1 mmol/l = 18.016 mg/dl.
How to read this page
How to read the numbers here
Every value on "Molar mass of glucose (C₆H₁₂O₆)" comes from the source named beside its section, never from an estimate of our own with no origin.
Where the data comes from
Each section of "Molar mass of glucose (C₆H₁₂O₆)" names its official source; the verification date sits at the top of the page.
What the number doesn’t tell you
C6H12O6’s molar mass shifts slightly with where the sample comes from, because one of its elements has an atomic weight published as a range, not a single value.
More about “Molar mass of glucose (C₆H₁₂O₆)”
C6H12O6 compared with water
At 180.156 g/mol, one molecule (or formula unit) of C6H12O6 weighs 10.0 times as much as one water molecule. A single gram of C6H12O6 holds roughly 3.3427 × 10²¹ units — a number that only makes sense because the mole exists.
Worth repeating, because "Molar mass of glucose (C₆H₁₂O₆)" depends on it: one element in C6H12O6 has an atomic weight published as a range by the IUPAC, so the third decimal place of the molar mass shifts a little with where the sample came from.
Words on this page
Atomic weight
The average weight of an element’s atoms, weighted by how abundant each isotope is in nature, in atomic mass units. For 14 elements CIAAW publishes a range instead of a single value, because that abundance varies a little from sample to sample.
Standard definition by CIAAW — Commission on Isotopic Abundances and Atomic Weights · Atomic weight
Mole
The SI counting unit for atoms, molecules or other entities: one mole is exactly 6.02214076 × 10²³ of them, by the definition fixed in 2019. It is what ties a mass in grams to a number of particles.
Standard definition by BIPM — Bureau International des Poids et Mesures (SI) · Mole
Standard uncertainty
The margin attached to a measured value, usually written in parentheses on the last digits. A constant that is "exact by definition" has zero standard uncertainty; a measured one, like the gravitational constant G, always carries some.
Standard definition by BIPM — Bureau International des Poids et Mesures (SI) · Standard uncertainty
Isotope
Atoms of the same element (same number of protons) with a different number of neutrons, and therefore a different mass. Carbon-12 and carbon-14 are isotopes of carbon; only the second one is radioactive.
Atomic number
The number of protons in an atom’s nucleus, written Z. It is this number, not the mass, that defines which element an atom is: every atom with 8 protons is oxygen, whether it has 8 or 18 neutrons.
Standard definition by IUPAC · Atomic number