Peptide Chemical Calculator

This Peptide Chemical Calculator application is a tool to calculate the molecular formulae, accurate mono isotopic and average masses of your peptide.  
You can work with a sequence in one- or  three-letter amino acid code, choose few popular modifications on N- and C-terminals or add disulfide bridges.

The masses are calculated using the following atomic weights:

H	Element Monoisotopic mass - 1.0078250
	Average mass - 1.0079400
C	Element Monoisotopic mass - 12.0000000
	Average mass - 12.0110000
N	Element Monoisotopic mass - 14.0030740
	Average mass - 14.0067400
O	Element Monoisotopic mass - 15.9949146
	Average mass - 15.9994000
F	Element Monoisotopic mass - 18.9984033
	Average mass - 18.9984000
P	Element Monoisotopic mass - 30.9737634
	Average mass - 30.9737600
S	Element Monoisotopic mass - 31.9720718
	Average mass - 32.0660000
Cl	Element Monoisotopic mass - 34.9688527
	Average mass - 35.4527000
Br	Element Monoisotopic mass - 78.9183361
	Average mass - 79.9040000