A “must have” for every mass spectroscopist, MS iCalc is a collection of handy mass spec calculators designed to help you quickly get numbers and information you use every day, like mass and mass/charge, elemental composition, isotope patterns, m/z values, peptide modifications, and much more.

Here’s the complete list:
• Chemical Formula: Enter an elemental formula on the “periodic table” keyboard, and view its mass, mass/charge, and other properties.
• Isotope Pattern Graph: View a zoomable graphical display showing a molecule’s isotope pattern, and specify multiple formulas to determine what resolution is required to separate them.
• Isotope Pattern Table: View a molecule’s isotope pattern.
• Elemental Composition: Enter an experimental m/z and a mass accuracy to view a list of matching elemental formulas.
• Peptide Sequence: Specify a peptide sequence (with optional modifications) to view its mass and mass/charge.
• Peptide Fragments: Enter a peptide sequence and calculate the m/z values of MS/MS fragment ions. You can choose which fragment types (y, b, etc.) to use.
• Amino Acids: View the names, symbols, and masses of the amino acids.
• Peptide Modifications: List available peptide modifications with their name, symbol, and mass shift.
• Weight / Volume Conversion: Convert from one set of weight or concentration units to another.