To calculate the amount of ultrafiltration for hemodialysis, the first step is to determine the dry weight of the patient, that is, the ideal target weight for the patient to feel comfortable after dialysis with no edema. After determining the dry weight, the patient should be weighed before each dialysis session, and the amount of ultrafiltration for each dialysis session is calculated by subtracting the dry weight from the weight weighed before dialysis. However, it should be noted that the ultrafiltration volume of each dialysis should not be more than 5% of the dry body weight. If it is more than 5%, there is a possibility of hypotension and other complications during the process of dialysis, which may lead to the patient’s discomfort, so it is very important to control the amount of drinking water intake in the inter-dialysis period.