You can use the standard dropper 1ml to drop 20 drops of single essential oil, and1ml is 200 drops. If used for incense, foot bath or bathing, a single essential oil does not need to be diluted by 6 drops each time, and can be used for about 33 times. When used for skin massage, a single essential oil needs to be diluted with base oil. For example, if you prepare a massage oil with a concentration of 3%, you can drop 3 drops of single essential oil into 5ml of base oil, and massage your face with only 5-6 drops each time, so that 5ml can be used for at least one week.