Peptide Molecular Weight Calculator

Amino Acid Sequence (1-letter code or FASTA format)

0 characters

Modifications

N-terminal Acetylation (+42.04 Da) C-terminal Amidation (−0.98 Da)

Valid Amino Acids

A C D E F G H I K L M N P Q R S T V W Y

Molecular Weight

0.00 Da

Length 0 aa

Modifications None

pI (Isoelectric Point) -

Charge at pH 7 -

Mass / Mole Conversion

Mass

⇄

Amount

Enter a value in either field to convert automatically.
Showing scientific notation for very small/large values.

Advanced Analysis

ℹ️ About This Calculator

This calculator computes the average molecular weight of peptides based on the amino acid sequence. It uses standard atomic weights and accounts for water loss during peptide bond formation.

Supported formats: Single-letter amino acid codes (A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W, Y) and FASTA format with headers.

Advanced features: Isoelectric point (pI) calculation, extinction coefficient estimation, amino acid composition analysis, and net charge calculation at any pH.