Quick Calculators

Molecular Weight Calculator

Molecular Weight Calculator

Molecular Weight & Advanced Visualization Tool

The Molecular Weight Calculator is an essential tool in chemistry, allowing you to quickly determine the molar mass (in grams per mole, g/mol) of any chemical compound. Understanding the molecular weight is crucial for tasks like calculating solution concentrations, stoichiometry, and performing accurate laboratory work. This calculator uses standard atomic weights for common elements to provide highly accurate results and a detailed elemental mass percentage breakdown, which is visualized in the chart below.

Learn more about atomic masses on IUPAC standards.

${totalWeightFormatted} g/mol

3D Structure Simulation (${formula})

Drag to rotate (Simulated Structure)

Mass Percentage Visualization (D3.js)

Composition & Mass

${breakdownRows}
ElementCountMass (g/mol)Percent (%)
TOTAL:${totalWeightFormatted} g/mol100.00 %
`; // Draw the charts after the containers are in the DOM drawD3Chart(result.breakdown); initThreeJSVisualization(formula, elementCounts); }/** * Main calculation handler function. */ function handleCalculate() { const formula = formulaInput.value.trim();if (formula === '') { renderResults(null, null, "Please enter a chemical formula to calculate.", {}); // Pass empty object return; }try { // 1. Parse the formula const elementCounts = parseFormula(formula);// 2. Calculate the weights const result = calculateMolecularWeight(elementCounts);// 3. Render success renderResults(formula, result, null, elementCounts); // Pass elementCounts on success} catch (e) { // 4. Render error console.error("Calculation Error:", e); renderResults(formula, null, e.message, {}); // Pass empty object on error } }// --- Event Listeners and Initial Load ---// Function to handle resize and redraw the chart/3D let resizeTimer; window.addEventListener('resize', () => { clearTimeout(resizeTimer); resizeTimer = setTimeout(() => { // Re-run calculation and render to redraw D3 chart and reset 3D dimensions handleCalculate(); }, 200); });// Attach event listeners calculateButton.addEventListener('click', handleCalculate); formulaInput.addEventListener('keydown', (event) => { // Trigger calculation on Enter key press if (event.key === 'Enter') { event.preventDefault(); // Prevent default form submission behavior (if any) handleCalculate(); } });// Optional: Auto-fill with an example and calculate on load document.addEventListener('DOMContentLoaded', () => { formulaInput.value = 'C6H12O6'; // Example: Glucose handleCalculate(); });