Free big three calculator
Big three calculator
Sun, Moon and rising sign — computed from your date, time and place.
Your Sun, Moon and rising signs from one birth date, time and place—each to a fraction of a degree, together on your dashboard.
The rising sign needs your birth time; the Sun and Moon can be found without one.
Free · No account needed · Past dates always free
Your big three are positions, not a forecast
Your daily mainstream horoscope says: “Your big three explain your whole personality.”
Three positions — the Sun's sign, the Moon's sign and the sign rising — computed from the date, the time and the place. They are the first three lines of a chart, not a personality test.
Your Sun sign is where the Sun stood when you were born, and your date almost always settles it. Your Moon sign is where the Moon stood, and your date usually settles it. Your rising sign is the sign coming up on the eastern horizon at that minute, and only your birth time settles it.
The tradition behind this page: Ptolemy, Tetrabiblos, and William Lilly, Christian Astrology (1647).
How the big three are found
- Step 1
Three positions, three inputs
The Sun’s sign comes from the date, the Moon’s from the date and the hour, the rising sign from the exact time and place.
- Step 2
What each one is
Each is a separate placement: the Sun and the Moon are bodies standing in a sign; the rising sign is the sign on the eastern horizon.
- Step 3
Why the third needs the time
The Sun moves about 1° in a day and the Moon about 13°, but the horizon turns through the whole zodiac, so without a birth time the rising sign is left out rather than guessed.
From your chart to your days
Your chart is the map. The next question is when — and that part is free for today and this week.
Your chart and any past day are free. Unlocking the year ahead is what shows you every window before it arrives.
See what unlocking costs →Questions about your big three
- What is the big three?
- Your Sun, Moon and rising signs—the three placements most often quoted together. The Sun’s sign comes from the date (and the hour, on the day the Sun changes sign), the Moon’s from the date and the hour, the rising sign from the exact time and place.
- Do I need my birth time?
- For the rising sign, yes. Without a time this page gives your Sun sign (with a flag on the day the Sun changes sign), the Moon’s noon position with its margin, and says the rising sign needs the time instead of guessing it.
- Is it free?
- Yes—no account and no email. Your chart, today and every date you have already lived are free; exact future days are a one-time unlock, never a subscription.
We compute your chart with the Swiss Ephemeris for the minute and place of your birth (for noon, when the time is unknown), in the tropical zodiac with Placidus houses, and print each position to a fraction of a degree. It is astronomy applied to your birth chart, not numerology, and it is the chart the rulebook reads when it looks at your days.
The rulebook encodes that tradition whole—four centuries of transit doctrine, written down as rules you can read, not a model that guessed. Read the methodology.
- Swiss Ephemeris precision
- Your exact birth time and place
- Past dates free to test
Find your big three—free
Date, time and place. No account, no sign-up, and the chart is yours to keep. Or test a past date first.