Enter Birth Details
Use east longitude as positive. Use west longitude as negative.
Example Data Table
Use this sample data to test the calculator.
| Birth Date | Birth Time | Time Zone | Latitude | Longitude | Ayanamsha | House System |
|---|---|---|---|---|---|---|
| 1990-01-01 | 12:00 | UTC +5 | 31.5204 | 74.3587 | Lahiri | Whole Sign |
| 1988-07-15 | 06:30 | UTC -4 | 40.7128 | -74.0060 | Raman | Equal House |
| 2001-11-22 | 21:45 | UTC +0 | 51.5072 | -0.1276 | Fagan Bradley | Whole Sign |
Formula Used
The calculator first converts local birth time into Universal Time. It then calculates Julian Day. Planetary tropical longitudes are estimated with simplified orbital formulas. The sidereal position is found by subtracting the selected ayanamsha.
House Number = floor(normalize(Planet Longitude − Ascendant) / 30) + 1
Aspect Orb = |Actual Separation − Aspect Angle|
Whole sign houses start from the rising sign. Equal houses start from the exact ascendant degree. Aspects are checked against conjunction, sextile, square, trine, and opposition angles.
How to Use This Calculator
- Enter the birth date and exact birth time.
- Select the correct time zone offset for the birth place.
- Enter latitude and longitude of the birth location.
- Choose an ayanamsha method.
- Select whole sign or equal house calculation.
- Set the aspect orb for major aspect detection.
- Press the calculate button.
- Download the result as CSV or PDF.
Sidereal Astrology Chart Guide
A sidereal astrology chart uses the visible star background as its main reference. This makes it different from a tropical chart, which follows the seasonal zodiac. Many Vedic and traditional systems prefer the sidereal method because it keeps zodiac signs closer to fixed stars.
Why Ayanamsha Matters
Ayanamsha is the angular difference between tropical and sidereal zodiacs. It slowly changes over time because of precession. A small change in ayanamsha can move a planet near a sign boundary. That is why the calculator includes Lahiri, Raman, Krishnamurti, and Fagan Bradley options.
Planets, Houses, and Signs
Planetary positions show where each body appears in the sidereal zodiac. Houses show life areas linked with those positions. Whole sign houses give each sign one complete house. Equal houses divide the chart into twelve equal sections from the ascendant degree. Both methods are useful, and many astrologers compare them.
Reading the Output
Start with the ascendant, Moon, and Sun. Then review the sign, house, nakshatra, and motion of each planet. Retrograde motion can mark a slower or more inward expression. Major aspects show angular relationships between bodies. Tight orbs are usually stronger.
Practical Use
This tool is designed for study, comparison, and report building. It can help students understand chart structure quickly. It also gives downloadable data for notes, client worksheets, or research. The formulas are simplified, so use a high precision ephemeris when exact professional accuracy is required.
FAQs
What is a sidereal astrology chart?
A sidereal chart places planets against the star-based zodiac. It subtracts ayanamsha from tropical positions to show sidereal signs.
What is ayanamsha?
Ayanamsha is the gap between tropical and sidereal zodiac positions. Different traditions use different ayanamsha values.
Which ayanamsha should I choose?
Lahiri is widely used in Vedic astrology. Raman, Krishnamurti, and Fagan Bradley are useful for comparison.
Does birth time matter?
Yes. Birth time affects the ascendant, houses, Moon degree, and some sensitive chart points. Use the most accurate time available.
What are whole sign houses?
Whole sign houses make the rising sign the complete first house. Each following sign becomes the next house.
What are equal houses?
Equal houses begin at the exact ascendant degree. Each house then covers exactly thirty degrees.
Can I export my result?
Yes. After calculation, use the CSV or PDF button to save the chart data and main report details.
Is this chart fully professional?
It is useful for learning and fast estimates. For exact professional work, compare results with a dedicated ephemeris.