An electronic vapor provision system includes a vaporizer for vaporising liquid for inhalation by a user of the electronic vapor provision system； a power supply comprising a cell or battery for supplying power to the vaporizer； a sensor for measuring the rate of airflow through the electronic vapor provision system as a result of the inhalation by the user； and a control unit for controlling the power supplied to the vaporizer based on a cumulative airflow for this inhalation by the user, wherein the cumulative airflow is determined based on the measurements of airflow rate by the sensor. Such a system allows the user control over the amount of vaporized liquid obtained in a given inhalation based on the cumulative airflow for the given inhalation.
