Birth Chart Calculator
Your natal chart is the sky at the moment you were born. This calculator uses a real astronomical ephemeris — not lookup tables — for all ten bodies, computes your Ascendant and Midheaven from sidereal time, and supports both Western (tropical) and Vedic (sidereal, Lahiri) zodiacs. Everything runs in your browser.
Unknown? Noon gives correct planets; the Ascendant needs the real time.
Use the offset in effect that day (mind daylight saving).
Frequently asked questions
- What do I need to calculate my birth chart?
- Your birth date, birth place, and birth time. The time matters most for your Ascendant and houses, which shift roughly every two hours. If the time is unknown, noon still gives you accurate planet-in-sign placements.
- Is this birth chart calculator accurate?
- Yes. It uses the Moshier astronomical ephemeris for all ten bodies, accurate to well within a degree, and computes your Ascendant and Midheaven from real sidereal time. Everything runs in your browser and your data is never sent anywhere.
- What is the difference between tropical and sidereal?
- Tropical (Western) astrology anchors the zodiac to the seasons; sidereal (Vedic) anchors it to the constellations, currently offset by about 24 degrees. The toggle recalculates your whole chart in either system.
- What house system does this calculator use?
- Whole sign houses, the oldest system in continuous use and the standard in Hellenistic and Vedic astrology. Your rising sign occupies the entire first house and each following sign takes the next house.
- Why is my Ascendant different from other websites?
- Small birth time differences, rounding, or a different zodiac setting (tropical vs sidereal) shift the Ascendant. If your birth time is near a sign boundary, even a few minutes changes the result.