# Calculators

This section contains tools for common calculations in mass spectrometry:

- For Fourier transform ion cyclotron resonance (FTICR) mass spectrometry: calculate resolving power and frequency for a given peak, based upon instrument parameters, and the acquisition time.
- From observed and theoretical m/z values, calculate the mass error in parts per million (ppm), calculate the theoretical m/z from a molecular formula, or calculate the m/z range for an m/z of interest plus/minus a mass error in ppm.
- Calculate the double bond equivalents (DBE) or hydrogen deficiency (Z) from a molecular formula.