0.138766
mol
138.766
mmol
138,765.5
umol
8.356656e+22
180.16
mg/mmol
0.138766
mol
138.766
mmol
138,765.5
umol
8.356656e+22
180.16
mg/mmol
The Grams to Moles Calculator quickly converts a given mass in grams to moles, millimoles, and micromoles using the substance's molar mass. This conversion is one of the most frequent calculations in chemistry laboratories, required for preparing solutions, performing stoichiometric calculations, and analyzing reaction yields. Whether you are a student solving homework problems or a researcher weighing out reagents, this tool provides instant results in multiple units. The formula is straightforward: n = m / M, where m is mass in grams and M is the molar mass in g/mol. Enter the mass you measured on the balance and the molar mass from the periodic table or chemical database, and get precise mole values in three convenient scales.
The conversion from grams to moles uses the equation:
n = m / M
Where n is the number of moles, m is the mass in grams, and M is the molar mass in g/mol.
The calculator also provides derived units:
To determine the molar mass of a compound, sum up all atomic masses in the molecular formula:
Always use consistent significant figures. If your balance reads to 0.01 g, your mole result is meaningful to about 3-4 significant figures, depending on the molar mass precision.
The result in moles is the standard unit for chemical calculations. Millimoles are useful when working with small quantities common in analytical chemistry and clinical settings (blood tests often report in mmol/L). Micromoles are standard in biochemistry for enzyme kinetics, drug concentrations, and microanalysis. Choose the unit most appropriate for your application.
Inputs
Results
n = 25 / 180.16 = 0.1388 mol = 138.8 mmol = 138,765 umol. This is roughly 1/7 of a mole of glucose.
Inputs
Results
n = 5 / 40.00 = 0.125 mol = 125 mmol. To make a 0.1 M NaOH solution, you would dissolve this in 1.25 L of water.
Look up each element's atomic mass on the periodic table and multiply by the number of that element in the formula. Sum all contributions. For example, CaCO3 = 40.08 + 12.01 + 3(16.00) = 100.09 g/mol. Online databases like PubChem also list molar masses.
Use millimoles (mmol) for analytical chemistry, clinical lab results, and small-scale reactions. Use micromoles (umol) for biochemistry, enzyme kinetics, and pharmacological calculations where quantities are very small, often in the microgram to milligram range.
Yes. For elements, use the atomic mass as the molar mass. For compounds, calculate the formula mass. For diatomic elements like O2, use the molecular mass (32.00 g/mol), not the atomic mass (16.00 g/mol).
Include the water of crystallization in your molar mass calculation. For CuSO4 * 5H2O: 63.55 + 32.07 + 4(16.00) + 5(18.015) = 249.69 g/mol. The water molecules are part of the formula unit.
Use the same number of significant figures as your least precise measurement. If your mass is 25.00 g (4 sig figs) and molar mass is 180.16 g/mol (5 sig figs), report the answer to 4 significant figures: 0.1388 mol.
Yes, simply multiply: m = n x M. If you have 0.5 mol of NaCl (M = 58.44 g/mol), the mass is 0.5 x 58.44 = 29.22 g.
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