Back

Our Methodology

How Skygram calculates compatibility — transparently, mathematically, and rooted in real astrological tradition.

Philosophy

Skygram uses a deterministic synastry algorithm — not AI guesswork — to score compatibility. We compute the actual angular relationships (aspects) between every planet in two birth charts, weight them by astrological significance, and normalize the result into a realistic score. Unlike simplistic systems, we score each planet-pair combination individually: a Venus–Moon conjunction is deeply nurturing, while a Saturn–Moon conjunction carries restriction. No positivity bias, no inflated numbers — just the geometry of the sky at the moment you were born.

Planetary Aspects

When two planets sit at a specific angular distance, they form an aspect — an energetic relationship. Unlike flat scoring systems, we evaluate each aspect contextually: the same aspect type (e.g. conjunction) scores differently depending on which planets are involved. A Venus–Mars opposition is magnetic attraction (+2), while a Saturn–Moon opposition is controlling (−3).

Conjunction0°
Context-dependent fusion−1 to +4
Trine120°
Natural harmony+1.5 to +2
Sextile60°
Gentle support+2
Opposition180°
Polarity — can attract or repel−4 to +2
Square90°
Friction & growth−5 to −1
Quincunx150°
Awkward adjustment−2

Planet Weights

Not all planetary contacts are equal. A Sun–Moon connection carries far more weight than a Neptune–Pluto one. We assign multipliers based on how personally significant each planet is.

Core (×3)

Sun, Moon, Venus, Mars, Ascendant

Shape identity, emotions, love & drive

Social (×2)

Mercury, Jupiter, Saturn

Communication, growth & commitment

Generational (×1)

Uranus, Neptune, Pluto, North Node

Deeper karmic & transformative themes

Orb Tightness

An aspect doesn't have to be exact to count — there's some leeway called the orb. A trine at exactly 120° is much stronger than one at 127°. We use a steep power curve (exponent 1.5) to scale each aspect's contribution: a tight orb carries nearly full weight, while wide-orb aspects contribute very little. Only tight, meaningful aspects drive your score. Luminaries (Sun & Moon) get a wider orb (up to 8°), personal planets up to 6°, and outer planets only 3°.

Relationship-Type Modifiers

Different kinds of relationships depend on different planetary energies. A romantic pairing cares most about Venus and Mars; a business partnership cares about Saturn and Mercury.

RomanticVenus–Mars ×2, Moon–Venus ×1.5, Moon–Sun ×1.8, Moon–Moon ×1.3, Venus–Venus emotional cross-bonus, geometric mean weights, sigmoid k=0.14 offset=3.5, diminishing returns per planet
FriendshipMercury–Jupiter ×2, Mercury–Mercury ×1.5, Sun–Sun ×1.5, Moon–Moon ×1.3, geometric mean weights, sigmoid k=0.10 offset=6.5, softened negatives 0.7×
BusinessSaturn–Mars boosted ×2, Mercury–Saturn ×1.5
FamilyMoon–Moon boosted ×2, Saturn–Node ×1.5

Five-Category Scoring

Instead of pooling all aspects into one sum (which lets one strong cluster dominate), we split the score into five independent dimensions. The final score (0–100) is the sum of all five. To score highly overall, you need strong contacts across every dimension — not just one.

Category weights vary by relationship type. For example, in friendship reports, Communication is weighted higher (up to 25) while Attraction & Values is weighted lower (up to 10), because what matters in a friendship is fundamentally different from a romance. Romantic reports use equal 20-point categories.

Emotional Bond

Moon–Sun, Moon–Moon, Moon–Venus, Moon–Saturn, Moon–Neptune, Moon–ASC, Venus–Sun & Venus–Venus (cross-bonus)

Attachment, safety, feeling seen and understood

Chemistry & Attraction

Venus–Mars, Venus–Venus, Venus–Sun, Moon–Mars

Polarity, sexual pull, magnetic chemistry

Communication

Mercury, Mercury–Jupiter, Mercury–Sun, Moon–Mercury

Mental flow, conflict style, intellectual rapport

Stability & Growth

Saturn, Jupiter, North Node, Moon–Jupiter

Longevity, stress tolerance, structural durability

Life Direction & Identity

Sun, Ascendant, Element Harmony, Moon–Sun

Purpose, worldview, shared meaning

Within each category, raw aspect points are passed through a sigmoid function that maps them to the category's max range. For romantic reports, k=0.14 with offset=3.5 means a zero raw score maps to ~35% (not 50%), so categories need genuinely positive contacts to score well. Romantic reports use a geometric mean for planet weight combinations instead of a sum, preventing any single high-weight pair from dominating a category.

Diminishing Returns

Instead of hard-capping the number of aspects per planet, we keep all aspects but apply diminishing returns with separate positive and negative ladders: positive aspects decay at [1.0×, 0.8×, 0.65×, 0.5×, 0.35×] while negative aspects use a softer ladder [0.7×, 0.55×, 0.45×, 0.35×, 0.25×]. This prevents negatives from disproportionately dominating. Each planet's total negative contribution is also capped at −8 raw points per category.

Generational Aspect Dampening

Outer planets (Uranus, Neptune, Pluto) move slowly and create aspects shared by entire generations. When an outer planet aspects Mercury, its contribution to Communication is reduced to 0.4× and capped at ±2 raw points. Similarly, negative outer-planet contributions to Growth are halved. Per-category negative floors prevent any single category from being completely zeroed out.

Friendship-Specific Scoring

Friendship compatibility uses adjusted scoring that reflects how planetary aspects manifest differently in non-romantic bonds:

Geometric mean weights & shifted sigmoid

Like romantic, friendship uses √(w1×w2) instead of w1+w2, and the sigmoid baseline (k=0.10, offset=6.5) requires genuinely positive contacts to score well.

Granular planet bonuses

Mercury–Jupiter ×2 (intellectual spark), Mercury–Mercury ×1.5, Sun–Sun ×1.5, Moon–Moon ×1.3, Sun–Mercury/Jupiter ×1.3, Moon–Venus ×1.2. No blanket Moon or Sun boosts.

Softened negatives (0.7×)

Negative aspects retain 70% of their weight — squares between friends are less painful than in romance, but still meaningful.

Continuous Improvement

Our methodology is not static. We continuously refine our aspect weights, orb allowances, and relationship modifiers based on user feedback and input from certified professional astrologers. If something doesn't resonate, let us know — your experience shapes how Skygram evolves.