In natal astrology, the Synthesis Sign (sometimes called the "integrated sign" or “weighted sign”) represents the zodiac sign that dominates and unifies the entire chart. Unlike the Sun, Moon, or Ascendant alone, the synthesis sign shows the overall tone of personality and the central integrating energy of an individual’s horoscope.

It answers the question:
👉“If I had to describe the chart’s whole energy as one sign, which would it be?”

🔹 Step 1: Collect Key Chart Factors

The calculation takes into account:

• Sun, Moon, Ascendant
• Mercury, Venus, Mars, Jupiter, Saturn
• Outer planets (Uranus, Neptune, Pluto)
• Optional points: Midheaven (MC), North Node

Each of these placements adds weight to the signs they are in.

🔹 Step 2: Assign Weights (Point System)

Different astrologers use slightly different systems, but a common method is:

• Sun, Moon, Ascendant: 3 points each
• Mercury, Venus, Mars: 2 points each
• Jupiter, Saturn, Uranus, Neptune, Pluto: 1 point each
• Midheaven or Node (optional): 1 point each

🔹 Step 3: Add Up the Signs

For each planet, add the points to the zodiac sign it occupies.
👉 Example:

• Sun in Aries = +3 Aries
• Moon in Gemini = +3 Gemini
• Venus in Gemini = +2 Gemini

Totals: Aries = 3, Gemini = 5 → Gemini has more weight.

🔹 Step 4: Identify the Synthesis Sign

The sign with the highest total points is the Synthesis Sign.
It represents the overall personality style and the dominant energy of the birth chart.

🔹 Step 5: Interpretation

• The Synthesis Sign modifies the Sun, Moon, and Ascendant expression.
• It often shows the true “center of gravity” of the person’s life energy.
• Example:
  • Sun in Taurus, Moon in Cancer, Ascendant in Leo.
  • After calculation, synthesis sign comes out as Gemini.
  • Meaning → although the person seems Taurean (Sun), nurturing (Moon in Cancer), and expressive (Leo Rising), at the core they function with a Gemini-like adaptability and curiosity.

🔹 Why It Matters

• Helps understand why someone doesn’t fully match their Sun sign stereotype.
• Brings clarity in career, relationships, and personal growth.
• Useful in psychological astrology to see the unified self-image.

✨ In summary:
The Synthesis Sign is the chart’s central integrating sign, calculated by assigning weights to all key planets and points. It represents the dominant zodiac influence, offering a holistic understanding of personality beyond the Sun, Moon, and Ascendant.