PeptideCalculator.Net is an online peptide and PNA molecular weight calculator.
It can calculate the average or monoisotopic molecular weights of peptides
including phosphorylated peptides. One can select from a variety of N-terminal
modifications like Biotin, 5-FAM etc. and optional linkers like aminobutyric
acid, aminohexanoic acid etc. The calculator displays the length of the peptide
in addition to the overall charge on the peptide. The peptide charge is
color coded displaying green for neutral peptides, red for acidic peptides and
blue for basic peptides. This is extremely useful in predicting the solubility of
peptides. It is also capable of calculating the molecular weights of
cyclic, lactam bridged and hydrocarbon stapled peptides. The PNA calculator
calculates the molecular weights of peptide nucleic acids.