A calibration system for calibrating power sensors includes a signal generator, a first signal splitter, a second signal splitter, a third signal splitter, a first measuring point, a second measuring point, a test port and a first power sensor. In this context, the signal generator is connected to the input of the first signal splitter. A first output of the first signal splitter is connected to the second signal splitter. A first output of the second signal splitter is connected to the test port. A second output of the second signal splitter is connected to the first measuring point. A second output of the first signal splitter is connected to the third signal splitter. A first output of the third signal splitter is connected to the first power sensor. A second output of the third signal splitter is connected to the second measuring point.