The Hormonal Forecaster is a freely downloadable software tool and calendar that assists users in determining ovulation and fertility using natural family planning techniques. Based upon recorded symptoms, the program can generate ovulation charts, fertility predictions, and other statistical information.  By predicting ovulation, it allows you to take advantage of your fertility to achieve or avoid pregnancy. The program uses proven techniques of natural family planning to calculate ovulation. Fertility calculations are based upon techniques such as the symptothermal (sympto-thermal) method, the billings ovulation method, and more. You can record various desired symptoms such as menstruation, basal body temperature, cervical mucus observations, cervix position, and other custom indicators using a convenient calendar interface. This software calculator will use this data to generate ovulation charts and predict ovulation. You can interpret your ovulation charts yourself or have the program do it for you with its fertility meter. The software aims to interpret fertility in an educational context so that users can also learn how ovulation charts are interpreted. At the same time, the Hormonal Forecaster can be completely autonomous so that users not interested in the details need not get involved.