Lewis Structure Generator

Enter a molecular formula and charge to draw a Lewis dot structure for common classroom molecules and ions. The generator includes tuned structures for common examples and a best-effort fallback for simple main-group formulas.

How This Lewis Dot Tool Works

The tool parses the formula, counts valence electrons using common main-group valences, adjusts for ion charge, and renders a Lewis-style SVG. Resonance structures and expanded octets can have multiple valid drawings, so treat the output as a classroom guide and verify formal charges for advanced work.

• Best supported: H2O, CO2, NH3, O3, SO4 2-, PCl5, SF6, CH4, BF3, and similar simple formulas.
• For polyatomic ions, choose charge explicitly before generating the structure.
• Use the SVG download for notes, presentations, and worksheets.