Peptide mass calculator (MH+)

Enter amino acid composition

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Nominal
Monoisotopic
Average

The computation of the molecular weight of a molecule, starting from a given formula, can be accomplished in three different way:

Nominal mass: In this case, the integer mass of the most abundant isotope of each element is used.

Monoisotopic (exact mass): In this case, the exact mass of the most abundant isotope of each element is used.

Average mass: In this case, the average atomic weight of elements is used