Apparatus and a method for deriving a power measurement summation for use in universal mobile telecommunications system user equipment are disclosed. Conversion from a logarithm scale to a linear scale for summation and back again is avoided. The technique obviates the need for a mathematical processor to convert power measurements in a logarithmic scale (e.g. decibels dB, or dBw) into a linear scale (e.g. mW) to sum the power measurements or a ratio. The summed power component is calculated using data stored in the device (e.g. look up tables) without any need for conversion of the scale used.