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Mass Spectrometry m/z Calculator

Mass-to-charge ratio for an ion.

Compute the mass-to-charge ratio (m/z) for an ion from its monoisotopic mass and charge state z. For multiply-charged ions, also reports the [M+nH]^n⁺ adduct m/z.

Dr. Helena Ortiz By Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

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Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

m/z = M / z; for protonated forms m/z = (M + n · 1.00728) / n.

In depth

Compute the mass-to-charge ratio (m/z) for an ion from its monoisotopic mass and charge state z. For multiply-charged ions, also reports the [M+nH]^n⁺ adduct m/z.