Native Mass Spectrometry Calculator

In native mass spectrometry, proteins and complexes retain their natural charge states, and converting between molecular mass, charge state (z), and m/z value is a routine but error-prone calculation. The Native Mass Spectrometry Calculator handles all three directions: select your calculation type — m/z from mass and charge, mass from m/z and charge, or charge from mass and m/z — then enter the known values to get your primary result alongside a secondary cross-check and mass per charge unit. You can also apply an adduct correction (e.g., H⁺ or Na⁺) for more precise results. Also try the Significant Figures Calculator (Chemistry).

Da
Da

Mass of adduct ion (e.g., 1.0078 for H+, 22.9898 for Na+)

Results

Primary Result

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Secondary Calculation

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Mass per Charge Unit

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Frequently Asked Questions

What is native mass spectrometry?

Native mass spectrometry is a technique that analyzes biomolecules in their native, folded state under non-denaturing conditions. It preserves protein complexes and non-covalent interactions, allowing measurement of intact molecular masses. See also our Crude Fibre Calculator.

How do I calculate m/z from molecular mass and charge?

The m/z ratio is calculated by dividing the molecular mass by the charge state: m/z = (Mass + z × Adduct Mass) / z, where z is the charge state and adduct mass accounts for ionization (typically 1.0078 Da for H+).

What charge states are typical in native MS?

Native MS typically produces lower charge states compared to denaturing conditions. Proteins often show charge states between +5 to +30, depending on their size, with larger proteins generally having higher charge states. You might also find our Isotope Distribution Calculator useful.

Why is adduct mass correction important?

Adduct mass correction accounts for the mass of ionizing species (like H+, Na+, or NH4+) that attach to the molecule during ionization. This correction is essential for accurate mass determination from m/z measurements.

How accurate are native MS mass measurements?

Native MS can achieve mass accuracy within 0.01-0.1% for well-resolved peaks. The accuracy depends on instrument calibration, resolution, and the complexity of the charge state distribution.

What is the relationship between charge state and m/z?

Higher charge states result in lower m/z values for the same molecule. Multiple charge states of the same molecule appear as a series of peaks with predictable m/z spacing, allowing charge state determination.