Professional-grade protein calculators for students and researchers. Calculate molecular weight, isoelectric point, extinction coefficients, and more — all free.
Calculate MW of a protein from its amino acid sequence in Da and kDa.
Count each amino acid residue in a protein sequence with full composition analysis.
Find the pI (isoelectric point) of any protein from its amino acid sequence.
Calculate molar extinction coefficient (ε) at 280 nm using Trp, Tyr, and Cys residues.
Calculate protein concentration from absorbance (A280), extinction coefficient, or standard curve.
Calculate gel composition, acrylamide volumes, and buffer amounts for SDS-PAGE.
Calculate dilution volumes for protein samples using C1V1 = C2V2 formula.
Calculate analyte concentration from ELISA absorbance values using linear or 4PL standard curves.
Calculate protein loading amounts, transfer buffer, blocking solution, and antibody dilutions.
Calculate total protein yield, recovery percentage, and purification fold at each purification step.
Look up molecular weights for all 20 standard amino acids in residue and free form with pKa values.
Calculate peptide MW, net charge at any pH, isoelectric point, GRAVY hydrophobicity, and extinction coefficient.
These free online protein tools are designed for biotechnology students, biochemistry researchers, and lab professionals. All calculations follow standard biochemistry formulas and reference values used in peer-reviewed research.
Whether you need to calculate the molecular weight of a recombinant protein, find the isoelectric point for purification optimization, or set up an SDS-PAGE gel — these tools provide accurate, instant results without any software installation.
All tools are verified by a trained biotechnology professional and are completely free to use.