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Chart Calculation - Complete Guide

Understanding Natal Charts

A natal chart (birth chart) is a snapshot of the sky at the exact moment and location of your birth. It shows the positions of planets, signs, houses, and aspects that describe your personality, strengths, challenges, and life path.


Required Information

Before You Start

To calculate an accurate natal chart, you'll need:

1. Chart Name

What: A unique identifier for this chart

Examples:

  • "My Chart" or "Me"
  • "John Smith"
  • "Mom", "Dad", "Sister"
  • "Business Partner"

Note: If you save a chart with the same name, it will update the existing chart rather than creating a duplicate.

2. Birth Date

What: Day, month, and year of birth

Format:

  • Day: 1-31
  • Month: 1-12 (or dropdown selection)
  • Year: Four digits (e.g., 1985, 1990, 2000)

Note: The system handles leap years and different calendar formats automatically.

3. Birth Time

What: Hour, minute, and AM/PM

Important:

  • Use 12-hour format (1-12) with AM/PM
  • Minutes: 0-59
  • The more accurate, the better

If you don't know your exact time:

  • Check your birth certificate - most official documents record birth time
  • Ask family members - parents or relatives may remember
  • Use 12:00 PM (noon) - creates a "solar chart" without houses
  • Approximate - morning, afternoon, evening (some info is better than none)
4. DST (Daylight Saving Time)

What: Was DST in effect at your birth?

DST Periods (typically):

  • Northern Hemisphere: March/April - October/November
  • Southern Hemisphere: October - March
  • Note: Not all countries/regions observe DST

How to know:

  • Check historical DST records for your birth location
  • The system will try to auto-detect based on date and location
  • When in doubt, verify with local historical records
5. Birth Place

What: City or town where you were born

How to enter:

  1. Start typing the city name in the "Place" field
  2. Autocomplete will suggest matching cities worldwide
  3. Select the correct city from the dropdown
  4. Coordinates (latitude, longitude) will auto-fill
  5. Time zone offset will be calculated automatically

Tips:

  • Include country or state if city name is common (e.g., "Paris, France" vs "Paris, Texas")
  • For small towns, try the nearest major city
  • Verify the coordinates are reasonable (latitude: -90 to +90, longitude: -180 to +180)

Step-by-Step Calculation Process

Step 1: Navigate to Chart Calculation
  • Click Calculate → Horoscope in the main navigation menu
  • You'll see the chart calculation form
Step 2: Fill in Birth Data
  1. Name: Enter a unique name for this chart
  2. Date: Select day, month, and year
  3. Time: Enter hour (1-12), minute (0-59), and select AM/PM
  4. DST: Select "Yes" if DST was in effect, otherwise "No"
  5. Place: Type city name and select from autocomplete suggestions
  6. Coordinates: Verify latitude, longitude, and time difference are filled correctly
Step 3: Calculate
  • Double-check all information for accuracy
  • Click the "Calculate" button
  • Wait a moment while the system performs astronomical calculations
Step 4: View Results

After calculation, you'll see a summary card with:

  • Birth data: Name, date, time, place
  • Sidereal time: Astronomical time at birth
  • Menu options: Links to different chart interpretations
Step 5: Explore Interpretations

Click any menu option to view detailed information (see sections below).


Understanding Your Chart Output

What it shows: A comprehensive personality analysis based on your Sun, Moon, and Ascendant (Rising Sign).

Includes:

  • Sun Sign: Core identity, ego, life purpose
  • Moon Sign: Emotional nature, instincts, inner self
  • Ascendant (Rising Sign): Outer personality, first impressions, approach to life
  • Synthesis: How these three main factors work together

Use it for: Understanding your fundamental nature and how you express yourself in the world.

What it shows: Where each planet expresses itself in your life.

The 12 Houses represent:

  • 1st: Self, appearance, approach
  • 2nd: Money, values, possessions
  • 3rd: Communication, siblings, local travel
  • 4th: Home, family, roots
  • 5th: Creativity, romance, children
  • 6th: Work, health, daily routine
  • 7th: Partnerships, marriage, contracts
  • 8th: Transformation, shared resources, death/rebirth
  • 9th: Higher education, philosophy, foreign travel
  • 10th: Career, reputation, public image
  • 11th: Friends, groups, hopes/wishes
  • 12th: Spirituality, hidden matters, subconscious

Use it for: Identifying which life areas are emphasized and how planetary energies manifest in specific contexts.

What it shows: HOW each planet expresses itself through the qualities of its zodiac sign.

Includes interpretations for:

  • Sun: Identity, ego, vitality
  • Moon: Emotions, instincts, needs
  • Mercury: Communication, thinking, learning
  • Venus: Love, beauty, values, relationships
  • Mars: Action, desire, aggression, drive
  • Jupiter: Growth, expansion, luck, philosophy
  • Saturn: Structure, discipline, limitations, lessons
  • Uranus: Innovation, rebellion, sudden change
  • Neptune: Dreams, spirituality, illusion, compassion
  • Pluto: Transformation, power, regeneration

Use it for: Understanding the style and flavor of each planetary function in your personality.

What it shows: The sign on each house cusp (beginning) describes your approach to that life area.

Example:

  • 7th House (partnerships) in Aries: You approach relationships directly, independently, perhaps impulsively
  • 10th House (career) in Cancer: You seek nurturing, security, or family-oriented careers

Use it for: Fine-tuning your understanding of how you naturally approach different life areas.

What it shows: Angular relationships between planets, showing how different parts of your psyche interact.

Major Aspects:

  • Conjunction (0°): Planets blend and intensify each other's energies
  • Sextile (60°): Harmonious, opportunity for easy cooperation
  • Square (90°): Tension, challenge, dynamic growth potential
  • Trine (120°): Natural harmony, ease, flow of energy
  • Opposition (180°): Polarization, need for balance and integration

Orbs: Aspects don't need to be exact. The system uses orbs (allowable degrees of separation):

  • Tight aspects (0-3°): Very strong influence
  • Wide aspects (4-8°): Moderate influence

Use it for: Understanding internal dynamics, conflicts, and talents in your personality.


Technical Details

Calculation Methods
  • House System: Placidus (time-based division)
  • Planetary Positions: Geocentric (Earth-centered)
  • Zodiac: Tropical (season-based, starting at Spring Equinox)
  • Calculation Engine: Battle-tested since 1984 (41+ years)
  • Accuracy: Sub-degree precision for all planetary positions
What's Included

Planets:

  • Sun, Moon, Mercury, Venus, Mars
  • Jupiter, Saturn, Uranus, Neptune, Pluto
  • North Node (karmic direction)

Angles:

  • Ascendant (Rising Sign)
  • Midheaven (MC)
  • Descendant (7th house cusp)
  • Imum Coeli (IC, 4th house cusp)

Tips for Best Results

Best Practices
  1. Verify birth time accuracy: Check birth certificate or official records
  2. Double-check location: Make sure you select the correct city (not just any city with the same name)
  3. DST verification: Research historical DST rules for your birth location and year
  4. Save your chart: Always save important charts so you can access them later
  5. Give meaningful names: Use clear, memorable names for saved charts
  6. Read multiple sections: Don't just focus on Sun sign - explore all interpretations for a complete picture
  7. Consider transits: Use "Planets Today" to see how current planetary positions affect your chart
  8. Use planetary hours: Time important activities based on your personalized planetary hours

Troubleshooting Common Issues

Solutions:

  • Try the nearest major city instead
  • Add country name (e.g., "Springfield, USA" vs "Springfield, UK")
  • Check spelling variations
  • Use the international name if available

Solutions:

  • Select a city from the autocomplete dropdown (don't just type and skip)
  • If problem persists, manually enter coordinates (you can find them via Google Maps)
  • Latitude format: Degrees (0-90) Minutes (0-59) Direction (N/S)
  • Longitude format: Degrees (0-180) Minutes (0-59) Direction (E/W)

Check:

  • Birth time: AM vs PM confusion is common
  • DST setting: Wrong DST can shift time by 1 hour
  • Location: Make sure you selected the right city (coordinates matter!)
  • Date: Verify day, month, year are correct
  • Time zone: System calculates automatically, but verify it's reasonable for your location

Ready to Calculate?

Now that you understand the process, calculate your natal chart!

Calculate Chart Now Back to Getting Started

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