Kepler's Laws Planetary Motion Select Calculation Calculate: Perihelion & Aphelion Distances (Law 1) Orbital Period (T) (Law 3) Semi-Major Axis (a) (Law 3) Central Body Mass (M) (Law 3) Perihelion & Aphelion Speeds (Law 2) Simple Solar System T²/a³ (Law 3) Inputs Central Body Mass (M): Custom Sun Earth kg Semi-Major Axis (a): m km AU Eccentricity (e): (dimensionless) Orbital Period (T): seconds days years Calculate Results Download Results (PDF)
