Why does my Western Chart differ from my Vedic Chart?
Indian Vedic Astrology uses the Sidereal Zodiac and traditional Western Astrology uses the Tropical Zodiac. The difference between these two zodiacs (known as the Ayanamsa value) is presently about 24 degrees growing to 30 degrees. Both systems are correct. However, between the two systems, depending on which astrological calculations are used, planetary positions may differ in terms of which houses and signs they are in. For most people living today, when considering their Vedic charts, all the planets and the rising sign would be found to be about 23 or 24 degrees earlier than in their Western charts, or basically nearly one full sign back.
Western Astrology is based on the orientation of the Earth to the Sun, and applies the “Tropical Zodiac”. Western Astrology assumes that every year the Sun at the Spring and Autumnal Equinoxes is at the first degree of Aries and Libra respectively, and at the first degree of Cancer and Capricorn at the Summer and Winter Solstices. Vedic calculations are described as being highly accurate as they are true astronomical calculations. “Sidereal Zodiac” much more closely matches the actual position and apparent movements of these constellations.