In astrology, the Part of Fortune, sometimes called Fortuna, is the most popular Arabic Part. Arabic Parts are sensitive points in a chart and are calculated using specific formulas whereby two planets or points are added together, and a third planet or point is subtracted from that result.
The Part of Fortune is calculated as follows:
For day charts, Ascendant + Moon – Sun
For night charts, Ascendant + Sun – Moon
Note that a chart is considered a day chart when the Sun is above the horizon (occupying any house from house 7 to 12), and a night chart when the Sun is below the horizon (occupying any of the first six houses).
The Part of Fortune represents worldly success and is associated with the physical body and health as well. It can be indicative of the career or vocation. The condition and placement of the ruling planet of the Part of Fortune (that is, the natural ruler of the sign in which the Part of Fortune is placed) are important to factor into the interpretation of this Arabic part. Worldly success and prosperity are associated with the Part of Fortune, and both its sign and house placement suggests innate abilities and talents–areas of life and qualities that are expressed naturally.
The Part of Fortune lies the same distance in longitude from the Ascendant as the Moon lies from the Sun. Therefore, if, for example, the Sun is conjunct the Moon in the natal chart, the Part of Fortune will lie close to the Ascendant; and if the Sun and Moon are in opposition in the natal chart, the Part of Fortune will lie close to the Descendant.
It is interesting to note that the Arabic part, the Part of Spirit, is calculated in an opposite manner, and also symbolizes the reverse or opposite theme of spiritual well-being.
JV ASTROLOGY 