Аннотация:We present a method of chromospheric flux simulation for 13 late-type main-sequence stars. These Sun-like stars have well-determined cyclic flux variations similar to an 11 year solar activity cycle. Our flux prediction is based on chromospheric HK emission time series measurements from Mount Wilson Observatory and comparable solar data. We show that solar three-component modelling explains the stellar observations well. We find that 5-10% of the disc surfaces of K stars are occupied by bright active regions.