A method for controlling an electrochromic device comprises obtaining (210) of a target colouring level and a measure of an initial colouring level. A measure of an initial open circuit voltage between electrodes of the electrochromic device is obtained (220). A voltage applied between the electrodes is calibration ramped (230). A calibration charging current is measured (232) during the calibration ramping of the voltage. The calibration ramping of the voltage is interrupted (236), intermittently and temporarily and a calibration open circuit voltage is measured (238). The calibration ramping is stopped (240) when a calibration condition is met. A constant main charging/discharging voltage between the electrodes of the electrochromic device is applied (250). The voltage is selected in dependence of the ramped voltage when stopped. Application of a voltage between the electrodes is removed (270) when target colouring level is reached. An electrochromic device capable of performing such procedure is disclosed.