Moles to Grams Calculator
Convert an amount of substance in moles into mass in grams using the molar mass, entered directly or derived from a chemical formula.
mol
g/mol
Mass of the given amount of substance
- 1
Molar mass M
18.015 g/mol - 2
Mass = moles × M
2 mol × 18.015 g/mol = 36.030
How does this calculator work?
To convert moles to grams, multiply the number of moles by the molar mass: mass (g) = moles × molar mass (g/mol). Find the molar mass by summing the atomic weights of every atom in the formula. For example, 2 mol of water (18.02 g/mol) equals about 36.03 grams.
Formula
How this is calculated
Enter the amount of substance in moles. The molar mass can be supplied two ways: type a chemical formula (such as H2O, NaCl, or C6H12O6) and it is computed automatically from standard atomic weights, or enter the molar mass directly in grams per mole. If both are given, the manual override takes priority.
The core relationship is mass = moles × molar mass. Molar mass is the mass of one mole of a substance (6.022 × 10^23 particles) expressed in g/mol, numerically equal to the substance's atomic or molecular weight in atomic mass units. The formula parser sums each element's atomic weight multiplied by its subscript, supporting parentheses and bracketed groups like Ca(OH)2.
Results assume the molar mass corresponds to the pure compound entered. Negative or non-numeric moles, an empty or unrecognized formula with no manual molar mass, and a non-positive molar mass all return no result. Atomic weights use IUPAC standard values, so very high-precision work may differ slightly.
Frequently asked questions
Add up the atomic weight of each element times the number of atoms of that element. For example, H2O is 2 × 1.008 + 15.999 ≈ 18.02 g/mol. This calculator does that automatically when you type a formula.
Moles count particles (one mole is 6.022 × 10^23 particles), while grams measure mass. Molar mass (g/mol) is the bridge: multiply moles by molar mass to get grams.
Yes. Use the molar mass override field if you already know it or your compound is not covered by the formula parser. The override is used in place of the formula-derived value.
Also known as
TG we-Calculate Editorial Team. (2026). Moles to Grams Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/moles-to-grams-calculator
TG we-Calculate Editorial Team. "Moles to Grams Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/moles-to-grams-calculator.
TG we-Calculate Editorial Team, "Moles to Grams Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/moles-to-grams-calculator
@misc{wecalculate_moles_to_grams_calculator, title = {Moles to Grams Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/moles-to-grams-calculator}}, year = {2026}, note = {TG we-Calculate} }
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