This peptide properties calculator reads an amino acid sequence and returns its molecular weight, net charge, isoelectric point, and composition.
How to use the Peptide Properties Calculator
- Paste the amino acid sequence.
- Read the result card. It updates as you type, and you can copy or share it.
About this calculator
Results assume a free N-terminal amine and free C-terminal acid with no modifications. Amidation, acetylation, cyclization, or non-standard residues change the true values.
pKa values vary between reference sets, so charge and pI can differ slightly from other tools.
Frequently asked questions
Why is my MW different from the vial label?
Labels may list monoisotopic mass, include salt forms such as acetate or TFA, or account for modifications.
Sources
- ProtParam tool. Expasy, SIB Swiss Institute of Bioinformatics.
- Bjellqvist B et al. The focusing positions of polypeptides in immobilized pH gradients can be predicted from their amino acid sequences. Electrophoresis. 1993;14:1023–1031. PubMed.
- Solubility guidelines for peptides. Sigma-Aldrich (Merck) technical library.
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- mg to mcg to IU Converter: This mg to mcg converter switches between grams, milligrams, micrograms, and nanograms, and converts to international units (IU) when you know the substance’s factor.
- Peptide Concentration Calculator: This peptide concentration calculator shows how strong your solution is after reconstitution, in mg/mL, mcg/mL, and mcg per insulin syringe unit.
- Peptide Reconstitution Calculator: This peptide reconstitution calculator shows how many units to draw after mixing a peptide vial with bacteriostatic (BAC) water. Enter the amount on the vial label, the water you added, and your dose.
Medical disclaimer. This calculator is for educational purposes only and is not medical advice. Results are mathematical estimates based on the values you enter. Many peptides listed here are not approved by the FDA for human use. Confirm every dose with a licensed healthcare provider or your approved study protocol, and follow the product label.
