Peptide Calculator | Molecular Weight & Properties Tool

Peptide Calculator

A reliable, fast tool to calculate key peptide properties: molecular weight, net charge, hydrophobicity, atomic formula, and more.

For best results, paste or type in a 1-letter amino acid sequence (e.g., ACDFGHKLMNP).

About the Peptide Calculator

This peptide calculator allows researchers, students, and professionals in biochemistry and molecular biology to quickly estimate important characteristics of peptides and small proteins. Paste your sequence, and instantly receive:

  • Molecular weight (Da) for mass spectrometry or synthesis planning
  • Net charge at pH 7 — predicts peptide's isoelectric trend and solubility
  • Hydrophobicity profile (Kyte-Doolittle) for membrane/intrinsic tendencies
  • Empirical chemical formula for stoichiometric calculations
  • Counts of cysteine, aromatic residues, and more

Supports standard 20 amino acids in 1-letter code (ACDEFGHIKLMNPQRSTVWY). Input is case-insensitive, extra spaces/line breaks are ignored.

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