Percentage strength for glucose is read as % w/v: grams of solute in 100 mL of solution. So 1% is 1 g per 100 mL, which for this compound works out at 0.055507 mol/L, and 0.9% is 9 g per litre or 0.049957 mol/L. The calculator takes a percentage and a volume and returns the grams to weigh, with the molarity and mg/mL equivalents beside it.
The figure comes from the formula. Glucose is 6 × 12.011 (C) + 12 × 1.008 (H) + 6 × 15.999 (O), which is 180.156 g/mol, taking standard atomic weights, and every page here computes that sum rather than quoting it. Oxygen makes up the largest share of the mass: 6 of the 24 atoms in a formula unit are oxygen, and they account for 95.994 g of the 180.156 g, or 53.28% by mass. The derivation table below breaks the whole molecule down element by element.
Three different percentages are in circulation and they are not interchangeable. Per cent w/v is mass in a volume, the one used here and on medical labels; per cent w/w is mass in mass, the one on drums of concentrated reagent; per cent v/v is volume in volume, used for liquids mixed into liquids. For a dilute aqueous solution w/v and w/w are within a percent of each other, but for anything concentrated the density has to come into it.
Blood sugar, dextrose in the kitchen and the standard carbon source in microbiology. Labs report it in mg/dL in the US and mmol/L elsewhere. At 180.156 g/mol it is heavier than 15 of the 21 organic compounds covered here, and that ranking matters more than it looks: uric acid has a molar mass of 168.112 g/mol, so a gram of it contains 7.16% more formula units than a gram of glucose. Weigh by mass and you are not weighing equal amounts of substance.
Two practical things move the result. Purity below 100% means the weighed mass overstates how much compound you have — at 98% assay, 3.6031 g of every 180.156 g is not the compound — and any water picked up from the air does the same. Both are systematic, so they shift every solution made from that jar in the same direction.
The formula
p- The strength you want, as % w/v
V- The volume of solution, in millilitres
m- The mass of glucose to weigh out, in grams
180.156- The molar mass of glucose in g/mol, derived from its formula
How it works, step by step
- Enter the percentage strength you want, as % w/v.
- Enter the volume of solution in millilitres.
- Grams needed is percentage × volume ÷ 100, since 1% w/v is 1 g per 100 mL.
- The molarity that strength corresponds to for glucose is shown beneath, using 180.156 g/mol.
Worked examples
0.9% w/v glucose in 500 mL
0.9% w/v is 0.9 g per 100 mL, so 500 mL needs 4.5 g. In molar terms that solution is 0.049957 mol/L, and it is 9 mg/mL if you are dosing by volume.
5% w/v glucose in 100 mL
5% w/v is 5 g per 100 mL, so 100 mL needs 5 g. In molar terms that solution is 0.27754 mol/L, and it is 50 mg/mL if you are dosing by volume.
10% w/v glucose in 1000 mL
10% w/v is 10 g per 100 mL, so 1000 mL needs 100 g. In molar terms that solution is 0.55507 mol/L, and it is 100 mg/mL if you are dosing by volume.
How to read your score
Frequently asked questions
What is the molar mass of glucose (C6H12O6)?
It is 180.156 g/mol. That is the sum of the standard atomic weights of every atom in the formula: 6 × 12.011 (C) + 12 × 1.008 (H) + 6 × 15.999 (O). One mole of glucose therefore weighs 180.156 g, and a gram of it is 5.5507 mmol.
What percentage of glucose is oxygen?
53.28% by mass. Each formula unit contains 6 oxygen atoms contributing 95.994 g of the 180.156 g total, so 100 g of glucose contains 53.28 g of oxygen and a kilogram contains 532.84 g of it.
How many grams of glucose make a 1% w/v solution?
1 g in 100 mL of solution, 5 g in 500 mL, 10 g in a litre. The percentage is fixed to the volume, not to the compound, so those masses are the same whatever is being dissolved — what changes with the compound is the molarity they come to.
What molarity is a 1% w/v solution of glucose?
0.0555074 mol/L, because 1% w/v is 10 g/L and 180.156 g/L is one molar. A 0.9% solution is 0.049957 mol/L and a 5% solution is 0.27754 mol/L.
Is % w/v the same as % w/w?
No. Per cent w/v is grams per 100 mL of solution; per cent w/w is grams per 100 g of solution. They coincide only when the solution has a density of 1.00 g/mL, which dilute aqueous solutions approximately do and concentrated ones do not. Labels on concentrated reagents are usually w/w.
What is 1% w/v in mg/mL?
10 mg/mL, since 1 g in 100 mL is 1000 mg in 100 mL. For glucose that is also 55.507 mmol/L, which is the form a dose calculation usually wants.
Percentage strengths of glucose
| Element | Atoms | Atomic weight | Contribution (g/mol) | By mass |
|---|---|---|---|---|
| Oxygen (O) | 6 | 15.999 | 95.994 | 53.28% |
| Carbon (C) | 6 | 12.011 | 72.066 | 40% |
| Hydrogen (H) | 12 | 1.008 | 12.096 | 6.714% |
| Total — one mole of glucose | 180.156 | 100% |
Standard atomic weights, IUPAC 2021. The contribution column is atoms × atomic weight, and the total is the molar mass this page uses: 180.156 g/mol.
| Strength | per 100 mL | per 500 mL | per 1 L | Molarity (mol/L) |
|---|---|---|---|---|
| 0.1% w/v | 100 mg | 500 mg | 1 g | 0.0055507 |
| 0.25% w/v | 250 mg | 1.25 g | 2.5 g | 0.013877 |
| 0.5% w/v | 500 mg | 2.5 g | 5 g | 0.027754 |
| 0.9% w/v | 900 mg | 4.5 g | 9 g | 0.049957 |
| 1% w/v | 1 g | 5 g | 10 g | 0.055507 |
| 2% w/v | 2 g | 10 g | 20 g | 0.11101 |
| 3% w/v | 3 g | 15 g | 30 g | 0.16652 |
| 5% w/v | 5 g | 25 g | 50 g | 0.27754 |
| 10% w/v | 10 g | 50 g | 100 g | 0.55507 |
| 20% w/v | 20 g | 100 g | 200 g | 1.1101 |
A 1% w/v solution is 1 g in 100 mL, which for this compound is 0.055507 mol/L because 10 g/L divided by 180.156 g/mol gives that figure.
| Compound | Formula | Molar mass (g/mol) | Millimoles in 1 g |
|---|---|---|---|
| Tris base | C4H11NO3 | 121.136 | 8.2552 |
| Paracetamol | C8H9NO2 | 151.165 | 6.6153 |
| Uric acid | C5H4N4O3 | 168.112 | 5.9484 |
| Glucose (this page) | C6H12O6 | 180.156 | 5.5507 |
| Aspirin | C9H8O4 | 180.159 | 5.5507 |
| Caffeine | C8H10N4O2 | 194.194 | 5.1495 |
| EDTA | C10H16N2O8 | 292.244 | 3.4218 |
Ordered by molar mass. The last column is 1000/M, which is the number a weighed gram actually gives you.