Molecular Weight & Molar Mass Calculator

Calculate the molecular weight and molar mass of any chemical compound.

Enter a chemical formula (e.g., H2O, C6H12O6, Ca(OH)2) to calculate its molecular weight and molar mass. The tool provides a detailed breakdown of each element's contribution.

Examples

Try these common compounds:

Water (H2O)

Basic

Calculate the molecular weight of water.

Chemical Formula: H2O

Custom Atomic Masses:

Unit: g/mol

Glucose (C6H12O6)

Basic

Calculate the molecular weight of glucose.

Chemical Formula: C6H12O6

Custom Atomic Masses:

Unit: g/mol

Calcium Hydroxide (Ca(OH)2)

Basic

Calculate the molecular weight of calcium hydroxide.

Chemical Formula: Ca(OH)2

Custom Atomic Masses:

Unit: g/mol

Sodium Chloride (NaCl)

Basic

Calculate the molecular weight of sodium chloride.

Chemical Formula: NaCl

Custom Atomic Masses:

Unit: g/mol

Other Titles
Understanding Molecular Weight & Molar Mass Calculator: A Comprehensive Guide
Master the calculation of molecular weight and molar mass for any chemical compound.

What is Molecular Weight & Molar Mass?

  • Definition and Importance
  • Difference Between Molecular Weight and Molar Mass
  • Units of Measurement
Molecular weight is the sum of the atomic masses of all atoms in a molecule. Molar mass is the mass of one mole of a substance, usually expressed in g/mol. Both are fundamental in chemistry for stoichiometric calculations, solution preparation, and understanding molecular properties.
Key Concepts

Sample Calculations

  • H2O: (2 × 1.008) + (1 × 15.999) = 18.015 g/mol
  • CO2: (1 × 12.011) + (2 × 15.999) = 44.009 g/mol

Step-by-Step Guide to Using the Calculator

  • Inputting the Chemical Formula
  • Using Custom Atomic Masses
  • Selecting the Result Unit
To use the calculator, enter the chemical formula in the input field. Optionally, you can override atomic masses for specific elements. Choose your preferred unit for the result.
User Instructions

Usage Examples

  • C6H12O6 with default masses
  • NaCl with Na=22.99, Cl=35.45

Real-World Applications of Molecular Weight Calculations

  • Laboratory and Research
  • Pharmaceuticals and Industry
  • Education and Teaching
Molecular weight calculations are essential in laboratory experiments, pharmaceutical formulations, and educational settings. They help determine reactant quantities, solution concentrations, and molecular properties.
Applications

Application Scenarios

  • Preparing a 1M NaCl solution
  • Calculating dosage in drug development

Common Misconceptions and Correct Methods

  • Confusing Atomic and Molecular Mass
  • Incorrect Formula Parsing
  • Unit Conversion Errors
Users often confuse atomic mass with molecular mass, misinterpret chemical formulas, or make unit conversion mistakes. This calculator ensures accurate parsing and conversion for reliable results.
Tips for Accuracy

Common Mistakes

  • Using H2O instead of HO2
  • Mixing up g/mol and Da

Mathematical Derivation and Examples

  • Formula Parsing Logic
  • Atomic Mass Summation
  • Worked Examples
The calculator parses the chemical formula, counts each element, multiplies by its atomic mass, and sums the results. Parentheses and nested groups are handled for complex formulas.
Mathematical Approach

Detailed Calculations

  • Ca(OH)2: Ca=40.078, O=15.999×2, H=1.008×2
  • C12H22O11: C=12×12.011, H=22×1.008, O=11×15.999