The present invention discloses a method for washing in a washing machine, which can measure an accurate washing load before actual washing is carried out. To do this, the present invention provides a method for controlling washing in a washing machine, including (a) introducing laundry into a drum of the washing machine, (b) measuring an initial washing load caused by the introduced laundry, (c) repeating water supply to the drum for a fixed time period for maintaining a minimum water level determined by the initial washing load, taking water absorbed to the laundry into account, (d) after the preset water supply time period, determining a final washing load in the drum based on a number of water resupply times for an elapsed time from the initial water supply, and (e) washing the laundry by a washing method preset according to the determined final washing load.