A washing machine includes a washing tub configured to accommodate laundry therein, a motor configured to rotate the washing tub, and a controller. The controller is configured to: determine a laundry amount and a laundry-tangled degree by using a plurality of types of data that are measured while rotating the washing tub at a specific rotational speed; set an allowable unbalance (UB) value corresponding to the laundry amount and the laundry-tangled degree; determine a UB value based on rotating the washing tub during a dewatering stroke; and control the motor to stop rotating the washing tub based on the UB value exceeding the allowable UB value.