Using our self-developed peptide calculator, we can realize the conversion of single letter and three letter forms of polypeptide sequence, and calculate the sequence length, molecular formula and molecular weight of polypeptide molecule.

instructions：

1. Please input the peptide sequence in single letter or three letter form. If the input mode is three letter, please separate each amino acid with -. For example, rrrrrrr or Arg-Arg-Arg-Arg-Arg-Arg-Arg

2. The peptide sequence only supports 20 conventional amino acids, and some unnatural amino acids can be checked in other modifications

3. N-terminal modification and C-terminal modification can be selected from the drop-down box, and other side chain modifications can be checked in other modifications