Electronic measuring apparatus, specifically for measuring the fuel consumption of a vehicle, is arranged to receive distance indicative signals from a speed sensor and rate of fuel flow signals from a flowmeter sensor. The values represented by these signals are then divided by suitable processing means, such as a microprocessor, and the resulting output signal provides an indication on a display of fuel consumption with respect to distance travelled. A manually activatable calibration circuit causes storage of the value of the speed-dependent signal at the moment of manual activation and the microprocessor makes use of this stored reference value as a weighting factor for the calculation of fuel consumption. Accordingly it is arranged that the manual activation of the calibration circuit should take place at a predetermined speed, and thenceforth other speeds are calculated on the basis of the predetermined speed corresponding to the value of the speed-dependent signal at the moment of activation of the calibration circuit.