Part of Fortune Calculator

What is the Part of Fortune?

The Part of Fortune (Pars Fortunae in Latin, marked with the glyph ⊗) is the most famous of the Arabic Parts (also called Lots), a family of calculated points that astrologers have used for over two thousand years. It isn't a planet or a star you can find in the sky; it's a single spot worked out from the relationship between three of the most important points in your chart: your Ascendant, your Sun, and your Moon.

Where the Sun is your core identity and the Moon is your emotional inner world, the Part of Fortune marks where the two come together with your rising sign to create a sense of ease. It's often read as the place of joy, well-being, prosperity, and natural flow, the corner of life where things tend to fall into place for you without forcing them. When you're aligned with your Part of Fortune, you feel lucky, healthy, and quietly at home in yourself.

How the Part of Fortune is calculated

The formula is elegantly simple, but it has a twist: it flips depending on whether you were born during the day or at night, what astrologers call your chart's sect.

The result is a single ecliptic longitude reduced to a value between 0° and 360°. Divide by thirty and you get the zodiac sign; the remainder is the degree within that sign. This calculator works out your sect from your birth details automatically, so you never have to choose the formula yourself.

Why your exact birth time matters

Every version of the formula begins with your Ascendant, your rising sign. The Ascendant is the point on the eastern horizon at the moment you were born, and it moves fast: through all twelve signs in twenty-four hours, roughly a new sign every two hours. A guess of “sometime in the morning” can easily land you in the wrong sign, which throws off the Part of Fortune entirely.

That's why this calculator asks for your exact birth time and won't give a result without it. The most reliable sources are your birth certificate, hospital records, or a baby book. If you can get within a few minutes, your Part of Fortune will be accurate to the degree.

A worked example

Say you were born in the late morning, with the Sun above the horizon, a day chart. Imagine your Ascendant lands at 15° Leo, which is 135° of ecliptic longitude; your Moon at 10° Scorpio (220°); and your Sun at 25° Cancer (115°). The day formula is Ascendant + Moon − Sun, so you work out 135 + 220 − 115 = 240°.

To turn 240° into a sign, divide by thirty: 240 ÷ 30 = 8, and the ninth sign from Aries (counting Aries as the first) is Sagittarius. The remainder gives the degree, so this Part of Fortune sits at 0° Sagittarius. Had you been born at night, the Sun and Moon would simply swap in the formula and the point would land somewhere quite different, which is exactly why your chart's sect matters so much. This calculator does all of this for you; the example is just to show there's no mystery in the arithmetic.

How to read your Part of Fortune

Start with the sign. It describes the flavour of ease that comes naturally to you, a Taurus Part of Fortune finds flow through comfort and steadiness, an Aquarius one through ideas and community. It isn't a second Sun sign; read it as the conditions under which you feel quietly lucky and well.

Next, the house, if your birth time gives one. The sign says how ease arrives; the house says where in life it tends to show up, the second house points to money and resources, the seventh to partnership, the tenth to work and public life. A Part of Fortune in the fifth house, for instance, suggests your well-being is fed by creativity, play, and romance more than by grinding alone.

Hold it lightly. The Part of Fortune isn't a guarantee of money or success, it's a pointer toward the activities and settings where you replenish most easily. Read it as an invitation: when life feels effortful, it names a direction worth leaning back toward.

Frequently asked questions

Related in your chart

The Part of Fortune is one of several calculated points worth knowing. Pair it with your lunar nodes (your karmic axis), your Black Moon Lilith, and your Chiron. Its meaning sharpens once you know the house it falls in, which your free birth chart reveals.