Formula used
Birth details are converted into Universal Time and a Julian day. Low-precision orbital elements estimate geocentric ecliptic longitudes. Zodiac, house, aspect, and balance rules then organize the report.
The Ascendant uses local sidereal time, obliquity, latitude, and longitude. Whole Sign and Equal houses are direct geometric divisions. Other house systems use a clearly labeled educational approximation.
How to use this calculator
- Enter the birth date, time, and place.
- Confirm latitude, longitude, and UTC offset.
- Select a zodiac and house system.
- Adjust aspect orbs when needed.
- Calculate, review, copy, print, or export results.
Example data
| Example | Date | Time | Location | Purpose |
|---|---|---|---|---|
| Known time | 15 March 1992 | 10:30 | London | Complete chart |
| Unknown time | 22 August 1988 | Unknown | Toronto | Planets without houses |
| Sidereal | 4 May 2000 | 18:45 | Delhi | Lahiri chart |
| Whole Sign | 11 January 1975 | 14:15 | Sydney | House comparison |
Frequently asked questions
Why does exact birth time matter?
It determines the Ascendant, Midheaven, house cusps, and time-sensitive points.
What happens when birth time is unknown?
The calculator uses noon internally and hides houses and angles.
What is the difference between tropical and sidereal?
They use different zodiac reference frameworks and produce shifted sign positions.
Which house system should I choose?
Placidus is common. Whole Sign offers simple thirty-degree houses.
What is an aspect orb?
It is the allowed distance from an exact planetary angle.
What does retrograde mean?
It marks apparent backward motion from Earth’s viewing perspective.
What is a chart ruler?
It is the planet ruling the Ascendant’s zodiac sign.
Are empty houses inactive?
No. Their signs, rulers, transits, and progressions still matter.
Are these calculations professional-grade?
They are educational approximations. Verify precision work with dedicated ephemeris software.
Is birth information stored?
Not automatically. Local saving only occurs when you choose it.