The dBCalculator software comprises five independent calculation tools. PLEASE NOTE: Calculations based on coherent vs incoherent levels yield very different results. If you see an unexpected result, please verify the uncorrelated/correlated setting of this app first dbmCalculator: This tools helps to add and subtract an arbitrary number of power levels expressed in units of dBm and watt. VoltageCalculator: This tools helps to add and subtract correlated and uncorrelated voltage levels. UnitConverter: This tool calculates for an entry using a unit such as dBm, dBW, mW, W, mV, V, dBV, dBµV and dBu the corresponding values for all other units, for individual impedance values.