The methods of calculating ovulation are as follows: 1. Menstrual date projection method: For women with regular menstrual cycle, you can project yourself according to the regularity of the previous menstrual cycle. If the color of the ovulation test paper is obvious, it means that ovulation will take place within 24-48 hours. 2. 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: monitoring the basal body temperature, the basal body temperature refers to the body temperature when waking up early in the morning, the body remains quiet, and the mood is also in a calm state, generally at the time of ovulation body temperature will rise 0.3 ℃ – 0.5 ℃, until 1-2 days before menstruation or the first day of menstruation, the body temperature and drop to the original level. The measurement must be done with a normal routine, the daily sleep time should be kept above 6 hours, and the measurement time should be approximately the same every day.