The LC–MS m/z Adduct Calculator is a comprehensive analytical chemistry tool designed for scientists, researchers, and LC–MS users who need precise mass-to-charge (m/z) calculations for electrospray ionization (ESI) experiments. This calculator converts neutral monoisotopic mass to m/z and also performs the reverse calculation from observed m/z to neutral mass, supporting both positive and negative ionization modes.

This tool includes commonly observed LC–MS adducts such as:

[M+H]+

[M+Na]+

[M+K]+

[M+NH4]+

[M+ACN+H]+

[M+2H]2+ and higher charge states

[M-H]−

[M+Cl]−

[M+HCOO]−

[M+CH3COO]−

[M+TFA]−

Designed for real laboratory workflows, this calculator:

Uses monoisotopic masses

Accounts for charge state (z)

Applies electron mass correction

Supports multi-adduct comparison

Allows custom adduct entry

Enables CSV export for data analysis

Whether you are performing small molecule analysis, metabolomics, pharmaceutical characterization, environmental screening, or forensic toxicology, this LC–MS m/z calculator helps you quickly validate expected ion species, confirm adduct assignments, and interpret high-resolution mass spectra with confidence.

This tool is especially valuable for:

Troubleshooting unexpected peaks in LC–MS spectra

Predicting adduct formation patterns

Verifying isotopic mass accuracy

Teaching mass spectrometry fundamentals

Supporting method development and validation

Built for precision and transparency, the LC–MS Adduct Calculator displays full calculation steps, including:

m/z = (M + Δ ± z·e) / z

where M is neutral mass, Δ is the adduct mass contribution, z is charge state, and e is electron mass correction.

If you need a reliable, scientifically grounded LC–MS mass-to-charge converter, this tool provides a practical and laboratory-ready solution for modern analytical chemistry.