Ovulation is the process of ovulation from the ovaries, the main methods of calculating ovulation are as follows: 1, menstruation date projection method: for women who usually have regular menstrual cycles, you can project yourself according to the pattern of previous menstrual cycles. If the color of the ovulation test paper is obvious, it means that ovulation will take place within 24-48 hours; 2, ultrasound detection method: women who have the conditions can go to the hospital to detect the maturity of the follicle development through ultrasound, the follicle is usually about 2-3mm, close to the ovulation day will gradually increase, in the first two days of ovulation day can reach 18mm On the day of ovulation, the follicle will increase to more than 20mm. If the observation day happens to be the day of ovulation, sometimes you can even see the follicle rupture on the ultrasound; 3, basal body temperature measurement method: basal body temperature refers to the body temperature in the early morning when you wake up, your body is quiet and your mood is in a calm state. Generally, the body temperature will rise 0.3℃-0.5℃ at the time of ovulation and continue until 1-2 days before menstruation or the first day of menstruation, when the body temperature drops to the original level again. The measurement must be done with a normal routine, with a daily sleep time of at least 6 hours, and the measurement time should be approximately the same every day. To sum up, there are more methods to calculate ovulation, and you can consult your doctor for the specific ovulation detection method according to your situation.