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A point in your birth chart

Find your Part of Fortune

Calculate your Part of Fortune from the Ascendant, Sun and Moon, using the day or night formula for your exact birth time.

An exact birth time is required.

Date of birth

Use the local birth date in the modern (Gregorian) calendar, from 1600 to today.

Time of birth

Local birth time. For 2:30 pm, enter 14:30.

If the end is at or before the start, the range ends the next day. Equal times cover a full day.

We check the whole period. The Ascendant and houses are left out.

We check the whole local day and show any possible sign changes. The Ascendant and houses are left out.

Placidus uses your birth time to calculate unequal houses. Whole Sign gives each sign one house. Both need an exact time.

Choose the matching town or city on the next step.

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Your chart is private. Sharing is always your choice.

What the Part of Fortune describes

The Part of Fortune, also called the Lot of Fortune, combines the Ascendant with the distance between the Sun and Moon. It is a calculated zodiac position, rather than a physical object in the sky.

Traditional astrology associates this point with material circumstances and bodily life. A reading considers its sign and the planet that rules that sign. The name does not promise wealth, good health or a lucky event.

Why the formula changes at night

Astriel uses the Sun's calculated position above or below the geometric horizon to choose the formula. Civil clock hour alone cannot establish that distinction.

Sun above the horizon
Ascendant + Moon − Sun
Sun below the horizon
Ascendant + Sun − Moon

Each value is a longitude measured from 0° Aries around the full 360° zodiac. Add or subtract 360° until the result falls between 0° and just below 360°.

For an arithmetic example, 100° + 250° − 40° gives 310°: 10° Aquarius. Reversing the Sun and Moon gives −110°, which wraps to 250°: 10° Sagittarius. These are example inputs, not a personal chart.

Read the sign through its ruler

A Fortune position in Taurus leads to Venus, the traditional ruler of Taurus. Venus's own placement adds context to the interpretation. A Fortune position in Sagittarius leads to Jupiter instead.

The result links to the sign guide. Use your full chart to inspect the ruler's placement; this calculator does not assign Fortune a house or calculate its aspects.

Birth-time limits and calculation method

An approximate or unknown time leaves this point unavailable. The Ascendant moves with time, and the day/night formula can change near the horizon. Astriel does not substitute noon.

The horizon calculation uses the apparent geocentric centre of the Sun, without atmospheric refraction, terrain or elevation. It is distinct from observed sunrise and sunset. Results near the horizon need particular care when the birth record is rounded.

Deborah Houlding's Part of Fortune reference describes the formula and nighttime reversal. Astriel uses its own engine and shows the inputs in your result.

Read Astriel's calculation methods