Your lagna is the sign that was rising in the east when you were born. Your rasi is the sign the Moon was in at that time. Your birth star is the nakshatra the Moon was in. The lagna changes about every two hours, so it needs a correct birth time. The rasi changes about every two days, and the star about once a day.
☕ Three questions about one moment
Think of the sky as a circle of twelve signs. These signs are the rasis. A birth chart asks three questions about the moment you were born.
Lagna: which sign was rising in the east? The Earth turns once a day. So all twelve signs rise in the east each day. A new sign rises about every two hours. Some signs rise faster than others. It also depends on where you live. The rising sign is house 1 of your chart. The other houses are counted from it. The lagna changes fast, so it needs a correct birth time.
Rasi: which sign was the Moon in? The Moon goes round all twelve signs in about 27 days. It stays about two and a quarter days in each sign. The sign it was in at your birth is your rasi. In a Tamil panchangam, 'your rasi' always means this Moon sign. It is not the Sun sign used in Western horoscopes. Sade Sati, Guru peyarchi and chandrashtamam are all counted from your rasi.
Birth star: which nakshatra was the Moon in? The same circle is also cut into 27 nakshatras. The Moon takes about one day to cross each one. The nakshatra at your birth is your birth star. Your family uses it for your star birthday. It also decides the order of your dasha periods.
What each one is used for
- Lagna: the first house of your chart. All twelve houses start here.
- Rasi: Sade Sati, Ashtama Shani, Guru peyarchi and chandrashtamam are counted from it.
- Rasi: daily and monthly rasi palan is read for it.
- Birth star: your star birthday each year.
- Birth star: your first dasha, and the order of all dashas after it.
- Your rasi is your Moon sign. It is not the Western Sun sign.
- A birth time rounded to the hour may give the wrong lagna. The lagna can change in a few minutes.
- No lagna or rasi is good or bad by itself. Each is only a starting point.
- Two panchangams can differ a little when the Moon is near the edge of a star.
Frequently asked questions
What is the difference between lagna and rasi?
The lagna is the sign rising in the east at your birth. The rasi is the sign the Moon was in. They are often different signs. The lagna changes about every two hours. The rasi changes about every two days.
Is my rasi my Moon sign or my Sun sign?
It is your Moon sign. In Indian astrology, your rasi is the sign the Moon was in at birth. The Sun sign is used in Western horoscopes. It is measured in a different way.
Why does a correct birth time matter?
It matters most for the lagna. The lagna moves through a whole sign in about two hours. If you were born near the change of a sign, a few minutes can change it. The rasi and star change slowly. A small error rarely changes them.
What is a pada?
Each nakshatra has four quarters. Each quarter is a pada. One rasi holds exactly nine padas. So some stars are shared by two rasis. Their first padas are in one sign, and the rest are in the next sign.
How do I find mine?
Add your birth date, time and place in the Nava app. The app works out all three for you.
Deep dive: from birth time to chart
How the three are worked out, step by step.
🌅 Finding the lagna
We take your birth time and your birth town. From these we find the point of the zodiac on the eastern horizon. The sign of that point is your lagna. It is house 1, and the next signs are houses 2 to 12.
Not every sign takes two hours to rise. Near the equator they are about equal. Farther north, some rise faster and some slower. So the same clock time can give a different lagna in Chennai and in Delhi.
🌙 Finding the rasi and the star
The Moon's sidereal longitude at your birth gives both. Sidereal means measured against the stars, after the ayanamsa is taken off. Each sign is 30 degrees. Each star is 13 degrees 20 minutes.
Nine padas make one rasi. To read more about the stars, see Nakshatra, explained. For the signs, see the twelve rashis.