Lot of Fortune: Formula, Sect, and House

Day and night arithmetic

Convert the Ascendant, Sun, and Moon into absolute tropical longitudes measured from 0° Aries. When the Sun is above the local horizon, Fortune = Ascendant + Moon − Sun. When the Sun is below the local horizon, Fortune = Ascendant + Sun − Moon. If the result is below 0° or at least 360°, add or subtract a full circle until it lies within the zodiac. The traditional formula reverses its solar and lunar terms between day and night charts.

A worked day-chart example

Suppose the Ascendant is 9° Leo (129° from Aries), the Sun is 4° Taurus (34°), and the Moon is 6° Aquarius (306°). The day formula gives 129 + 306 − 34 = 401°. Subtract 360° to obtain 41°, or 11° Taurus. This example illustrates the arithmetic only: three invented longitudes do not establish that the Sun was physically above the horizon for a real place and moment. For an actual record, use the calculator's solar-altitude test.

Sect and uncertainty

A night birth with those same longitudes would use the reverse arc: 129 + 34 − 306 = −143°, equivalent to 217° or 7° Scorpio. The difference is substantial. A familiar source of disagreement between charts is applying the day equation to a night birth. Another source is a historical UTC offset or an approximate birth time. Near sunrise or sunset even a small correction can switch sect. At a polar horizon the Ascendant may be undefined, so a precise lot should be withheld rather than fabricated.

Reading Fortune with restraint

Historical authors associated Fortune with embodied circumstance and material conditions, but their interpretations vary. House placement, rulers, and aspects were studied in a full chart. One sign or house position alone cannot establish wealth, health, or a specific life event. This site labels the Whole Sign house as a reading aid and shows the raw degree so readers can examine other house methods in a full chart.