Mass Spectrum Predictor
In short: Import by PubChem name, draw a molecule, paste SMILES, or enter a formula to estimate monoisotopic mass, average mass, molecular ion peak, M+1/M+2 isotope peaks, and an isotope pattern chart. It is free, works in your web browser and needs no download.
Import a compound by PubChem name, draw a molecule, paste SMILES, or enter a molecular formula to estimate isotope pattern peaks, monoisotopic mass, average mass, and the molecular ion region.
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Predicted Spectrum
What This Mass Spectrum Tool Predicts
This tool predicts isotope distribution from elemental composition. It is useful for molecular ion peak checks, M+1/M+2 pattern interpretation, chlorine/bromine isotope patterns, and exact mass teaching.
- Monoisotopic mass: mass from the lightest common isotopes.
- Average mass: abundance-weighted molecular mass.
- Isotope pattern: relative molecular ion peaks from natural isotope abundances.
This is not an EI fragmentation or MS/MS predictor. Fragment ions depend on ionization method, collision energy, instrument settings, and molecule-specific fragmentation pathways.
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