Part of Fortune Calculator

What is the Part of Fortune?

The Part of Fortune (Latin: Pars Fortunae, also called the Lot of Fortune) is the most famous of the 'Arabic parts' or Lots inherited from Hellenistic astrology. It is not a body in the sky but a calculated point: the distance from the Sun to the Moon, projected from the Ascendant. Traditionally it signifies the body, livelihood and circumstances - where life tends to flow in your favour when you work with your chart rather than against it.

The formula flips with the Sun's position. For a day birth (Sun above the horizon): Part of Fortune = Ascendant + Moon − Sun. For a night birth: Ascendant + Sun − Moon. Getting the switch wrong gives you the mirror point (which is actually the Part of Spirit) - a common silent error in quick calculators. This one checks whether the Sun was above or below your horizon at your birth moment and applies the right formula, showing its working under your result.

How this calculator works

Give it the three birth details and it computes everything itself: your Ascendant from local sidereal time at your birthplace, the Sun's and Moon's true positions from standard astronomical formulas (Meeus), and the Sun's altitude to decide the day/night formula. The calculation is displayed under your result so you can verify it against any chart. Everything runs in your browser - nothing is uploaded.

Part of Fortune in the 12 signs at a glance

Frequently asked questions

Why do other Part of Fortune calculators ask for degrees?

Because the point is traditionally calculated FROM a finished chart - you look up your Ascendant, Sun and Moon longitudes and combine them. This calculator removes that step: it computes all three positions from your birth date, time and city, and applies the formula for you.

What is the Part of Fortune formula?

Day birth (Sun above the horizon): Ascendant + Moon − Sun. Night birth: Ascendant + Sun − Moon, all in zodiac longitudes (0-360 degrees). This calculator determines day or night from the Sun's actual altitude at your birth moment and place, then uses the matching formula - and shows you which one it used.

What does my Part of Fortune sign mean?

Traditionally, the sign describes the style in which fortune and ease come to you - the approach that tends to prosper. The reading under your result summarises it for your sign. The house (which a full chart adds) shows the life area; the sign shows the manner.

What if I was born right at sunrise or sunset?

Then the Sun was within a degree or so of your horizon, and honest astrologers disagree about which formula to use. In that rare case, compute both ways and read the point that also matches the rest of your chart - the two results are mirror images around your Ascendant-Moon arc.

Is the Part of Fortune the same as the Part of Spirit?

No - they are twins with the formula reversed. The Part of Spirit uses Ascendant + Sun − Moon by day. If a calculator gives you a point exactly as far on the other side, it has likely applied the Spirit formula or the wrong day/night switch.

More astrology calculators

Astrology Calculators - All ten sign calculators in one place. Sun Sign Calculator - Your core sign from your birth date. Moon Sign Calculator - Your emotional sign from birth date and time. Rising Sign Calculator - Your ascendant from birth time and place. Sun, Moon & Rising Calculator - Your Big Three in one calculation. Venus Sign Calculator - Your love and attraction style. Chiron Sign Calculator - Your wound-and-gift placement. Lilith Sign Calculator - Your Black Moon Lilith sign. North Node Calculator - Your growth direction and comfort zone. Vertex Calculator - Your point of fated encounters.

ToolFoxHub astrology calculators are for entertainment and self-reflection. Astrology is a symbolic tradition, not a science, and these readings are traditional interpretations, not facts or advice. Positions use the tropical zodiac and standard astronomical formulas (Jean Meeus) computed in your browser - nothing you enter leaves your device. Results agree with professional ephemerides for the great majority of births; if you were born in the short window when a body was changing sign, your exact birth time and place decide the answer, and the calculator says so when that is the case.