Arabic Parts Calculator — Every Hellenistic Lot on Your Chart

What an Arabic Part is

A lot is a derived point, not a physical body. Nothing sits there in the sky. It is a calculated degree that stands for a topic. You take one position, measure how far another is ahead of it, and then count that same distance starting from your Ascendant. Where you land is the lot.

The oldest and best known is the Lot of Fortune. It measures from the Sun to the Moon and projects from the Ascendant. Because the Sun and Moon shift through the zodiac, Fortune falls somewhere different in every chart. That single point became the seed for dozens of other lots, each pairing different starting points to talk about different parts of a life.

The name 'Arabic Parts' is a later habit. Arab and Persian astrologers preserved and expanded the technique, but the lots themselves come from Hellenistic writers of the first centuries. When we say 'lot' and 'part' here, we mean the same thing.

How we cast the whole set

Every lot here runs through one generator. It reads the two operand positions, works out the arc between them, and adds that arc to the Ascendant. Then it wraps the result back into the zodiac circle. One helper produces all of them, so the arithmetic is identical for each and nothing is tuned by hand.

For most lots the arc flips in a night chart. A formula given as 'from A to B' means, by day, the Ascendant plus B minus A. By night the same authors measure it the other way. We follow that sect rule and flag each lot that does not reverse, such as the lots of siblings and children, which keep one formula for both sects.

Once the degree is found, we assign it to a house using your own chart cusps and name its classical ruler. The lord matters more than the lot's sign in traditional reading, because the lord's condition tells you how the topic tends to behave.

What you get back

Enter your birth details and the tool returns a table of the classical lots, each with:

• Its glyph, name and the topic it stands for.
• The exact degree and sign it falls in.
• The whole-sign house it occupies on your chart.
• The classical ruler of that sign, called the lord of the lot.
• A short note on the sect rule and the ancient source behind that lot.

Reading the lots together

The four principal lots travel as a pair of pairs. Fortune speaks to the body, chance and material circumstances. Spirit, also called the Daimon, speaks to mind, intention and how you act on the world. Where Fortune is what happens to you, Spirit is what you do about it.

Eros and Necessity mirror them. Eros is desire and attraction, the pull toward what you want. Necessity is compulsion and fate, the binding that meets you whether you choose it or not. Read together, the four sketch a life as body, purpose, longing and limit.

The family lots — father, mother, siblings, children — and the marriage lots add specificity. Traditional writers judged them by the sign they occupied, the planets placed on them, and the condition of their lords. A benefic sitting near a lot softened its topic; a malefic brought effort or loss. The same logic runs through every entry here.

Lots reward confirmation. A single lot rarely proves anything on its own. When a lot, its lord, and an ordinary planet all point the same way, the theme reads strong. When they disagree, the truth is usually mixed, and that is worth more than a tidy answer.

A worked example: a night birth

Take a chart cast for 1 January 2000 at 17:30 in London, with the Ascendant at 28.81 degrees of Cancer. The Sun is below the horizon, so this is a night birth, and the reversals apply. The measured table is what the tool prints for exactly these inputs.

The Lot of Fortune falls at 23.33 degrees of Virgo in the third house, ruled by Mercury. The Lot of Spirit sits at 4.28 degrees of Gemini in the eleventh house, also ruled by Mercury. Notice the two luminaries swap which arc they open: on a night chart Fortune runs from the Moon to the Sun, and Spirit from the Sun to the Moon.

Eros lands at 17.86 degrees of Scorpio in the fifth house under Mars. Necessity answers at 9.75 degrees of Aries in the tenth, also under Mars. The family lots follow: Father at 29.02 Pisces in the ninth, Mother at 14.57 Leo on the first, Siblings at 13.68 Cancer in the twelfth, and Children at 13.93 Leo in the first. Because siblings and children are not reversed, they hold the same formula by night as by day.

The two marriage lots sit on either side of the seventh. The lot for a man's wife is at 20.26 degrees of Aquarius in the seventh, ruled by Saturn. The lot for a woman's husband is at 7.36 degrees of Capricorn in the sixth, also ruled by Saturn. Every figure above is produced by the shared generator and checked by our verification script.

What this tool does not claim

The arithmetic is exact and reproducible, but a lot is a marker, not a measured body. No planet, ray or field is emitted from it. Its meaning is a inherited symbolic convention, thousands of years of reading practice, not a tested physical effect.

Sources disagree. Different Hellenistic and medieval writers reversed different lots by night, and some topics have several competing formulas. Where we make a choice, we say so and name the authority. A lot that is disputed in the tradition is not settled by one calculator.

The house column uses your quadrant cusps by default, so the lot's house can differ under whole-sign or another system. The degree and sign never change; only the house label does.

How it relates to the other lot tools

This page is the wide view: every classical lot at once, so you can see the whole derived landscape. The dedicated pages go deep on one topic at a time, and the lot-activation and twelfth-part tools read those same points against the rest of the chart. Start here to find which lots sit interestingly on your chart, then drill into the ones that pull you.

Our method in one line

Every lot is projected from the Ascendant with a single shared generator on sub-arcsecond astronomy (VSOP87/ELP via astronomy-engine), using the sect rule of the classical sources, assigned to Porphyry quadrant houses (whole-sign available on every chart) cusps and ruled by the traditional domicile table. The worked-example degrees are reproduced by an automated check. Reviewed by Dr. Amara Osei, Astronomy Reviewer.