How do you calculate the molar mass of water (H2O)?

Water has 2 Hydrogen atoms (2 × 1.008 = 2.016 g/mol) and 1 Oxygen atom (15.999 g/mol), giving a total molar mass of `18.015 g/mol`.

Does the calculator support parentheses and chemical hydrates?

Yes, the parser evaluates parentheses such as `Ca(NO3)2` and dot-hydrates like copper sulfate pentahydrate `CuSO4*5H2O`.

What units are used for molar mass?

Molar mass is universally expressed in grams per mole (g/mol) or Daltons (Da) / unified atomic mass units (u).

How is percent elemental composition calculated?

Percent composition of element X = `[(Total Mass of Element X in Formula) / (Total Molar Mass)] × 100%`.

What is Avogadro's number in molar mass calculations?

Avogadro's constant ($6.02214076 \times 10^{23}$ particles/mol) represents the exact number of atoms or molecules contained in 1 mole of a substance.

Science & Engineering Cluster

Molar Mass Calculator (Molecular Weight & % Composition)

Calculate formula molecular weight and elemental mass percentage composition for chemical formulas.

TL;DR: Molar Mass Calculator computes the molecular weight and molar mass in grams per mole (g/mol) for chemical formulas, hydrates, and complex coordination polymers.

Chemical formula (e.g. H2O, C6H12O6, Ca(OH)2)

How Do You Calculate the Molar Mass of a Chemical Formula?

Molar mass is calculated by multiplying the standard atomic weight of each element by its stoichiometric count (subscript) and summing the totals: Molar Mass = Σ (Atomic Weight × Element Count). For example, Glucose (C₆H₁₂O₆) = (6 × 12.011) + (12 × 1.008) + (6 × 15.999) = 180.156 g/mol.

How to Use the Molar Mass Calculator

Our Molar Mass Calculator performs high-precision mathematical operations directly in your browser with zero latency and complete client-side privacy.

Enter a chemical formula into the input field (e.g., H2SO4, Ca(OH)2, Fe2(SO4)3·9H2O).
Click 'Calculate Molar Mass' (case-sensitive element symbols supported).
Review the total molar mass in g/mol and kg/kmol.
Inspect the elemental breakdown table showing atomic weight, atom count, and mass percentage (%).
Copy results for stoichiometry, yield calculations, or laboratory reports.

Mathematical Formula & Equations

Calculates total molecular weight in g/mol from chemical formulas (e.g. $\text{H}_2\text{SO}_4$, $\text{C}_6\text{H}_{12}\text{O}_6$).

\[ \text{Molar Mass} = \sum (n_i \times \text{Atomic Weight}_i) \]

Calculation Example

For water ($\text{H}_2\text{O}$): $2(1.008) + 1(15.999) = 18.015\text{ g/mol}$.

100% Client-Side Privacy & Data Security

All calculations, amortization schedules, variables, and sensitive numerical datasets execute 100% locally in your web browser memory. Your financial, medical, and personal values are never transmitted, logged, or uploaded to any external server.

Frequently Asked Questions

: Water has 2 Hydrogen atoms (2 × 1.008 = 2.016 g/mol) and 1 Oxygen atom (15.999 g/mol), giving a total molar mass of `18.015 g/mol`.
: Yes, the parser evaluates parentheses such as `Ca(NO3)2` and dot-hydrates like copper sulfate pentahydrate `CuSO4*5H2O`.
: Molar mass is universally expressed in grams per mole (g/mol) or Daltons (Da) / unified atomic mass units (u).
: Percent composition of element X = `[(Total Mass of Element X in Formula) / (Total Molar Mass)] × 100%`.
: Avogadro's constant ($6.02214076 \times 10^{23}$ particles/mol) represents the exact number of atoms or molecules contained in 1 mole of a substance.

Cite This Calculator

Need to reference this online calculator in a financial proposal, academic paper, blog post, or classroom curriculum? Copy a citation below.

NexLove.org. (2026). Molar Mass Calculator [Online Calculation Tool]. https://nexlove.org/tools/molar-mass-calculator

“Molar Mass Calculator.” NexLove.org, 2026, nexlove.org/tools/molar-mass-calculator.

NexLove.org (2026) Molar Mass Calculator. Available at: https://nexlove.org/tools/molar-mass-calculator (Accessed: 2026).

@misc{nexlove_molar_mass_calculator,
  title = {Molar Mass Calculator},
  author = {{NexLove.org}},
  year = {2026},
  url = {https://nexlove.org/tools/molar-mass-calculator}
}

Embed This Tool

Add the live Molar Mass Calculator to your own website with this snippet — it loads the real, working calculator in an iframe.

<iframe src="https://nexlove.org/embed/molar-mass-calculator.html" width="100%" height="600" style="border:1px solid #e2e8f0;border-radius:12px" title="Molar Mass Calculator — NexLove.org" loading="lazy"></iframe>

Related Science & Engineering

Molarity Calculator

pH Calculator

Browse all Calculators