Fast & Accurate Chemistry Tool
Molar Mass & Mole Converter
Enter any chemical formula to calculate its molecular weight, molar mass, elemental composition percentages, and atom counts with 4-decimal precision.
118
118 Elements
Nₐ
4 Decimals
100%
100% Client-Side
Molecular Weight
All 118 elements · IUPAC 2021 atomic weights
Quick examples:
Enter a chemical formula above to calculate molecular weight
Step-by-Step Guide
How to Calculate Molecular Weight
Calculate chemical formula mass in three simple steps.
Input a Chemical Formula
Type any chemical formula — H₂O, C₆H₁₂O₆, NaOH, or even complex structures with parentheses and brackets. The molar mass calculator identifies each element, resolves nested groups, and counts every atom. All 118 elements from the periodic table are supported.
NaOH
↓
Na × 1O × 1H × 1
FAQ
Frequently Asked Questions
Find answers to common questions about molecular weight calculations and chemistry formulas.
Molar mass is the mass of one mole of a substance, expressed in grams per mole (g/mol).
To calculate molar mass: (1) identify each element in the formula, (2) look up each element's standard atomic weight from the IUPAC periodic table, (3) multiply each atomic weight by its atom count, and (4) sum all products.
The Avogadro constant (Nₐ) is exactly 6.02214076 × 10²³ mol⁻¹, as defined by the 2019 redefinition of SI units.
Use the formula: moles = mass (g) ÷ molar mass (g/mol).
Numerically, yes — molar mass and molecular weight have the same value.
Ionic compounds like NaCl don't form discrete molecules, so technically we use 'formula mass' rather than 'molecular mass.' However, the molar mass calculation is identical: sum the atomic weights of all atoms in one formula unit.
This calculator provides molar mass values to 4 decimal places using IUPAC 2021 standard atomic weights.