A method for operating a high-pressure discharge lamp with a variable power is disclosed. Said method utilizing at least the following steps: (a) providing high-pressure discharge lamp, which has a nominal operating power; (b) operating the lamp with an instantaneous power, where the instantaneous power lies within relative lower and upper power limits, respectively, and said limits may depend on an average power, and said instantaneous power may lie within a predetermined absolute lower and upper power limit; (c) determining the average power from a one-sided moving average value of the instantaneous power or the exponential smoothing of the instantaneous power of a time segment of predefined length.