Understanding Spherical Coordinates
Spherical coordinates describe a point in three-dimensional space using three values: the radial distance r from the origin, the polar angle θ (theta) measured from the positive z-axis, and the azimuthal angle φ (phi) measured from the positive x-axis in the xy-plane.
Conversion Formulas
Cartesian to Spherical
Convert (x, y, z) to (r, θ, φ) using these formulas.
r = sqrt(x² + y² + z²)
Polar Angle θ
The angle from the z-axis down to the point.
θ = arccos(z / r)
Azimuthal Angle φ
The angle in the xy-plane from the x-axis.
φ = arctan2(y, x)
Spherical to Cartesian
Convert (r, θ, φ) back to (x, y, z).
x = r sinθ cosφ, y = r sinθ sinφ, z = r cosθ
Convention Note
This calculator uses the physics convention (ISO 31-11): θ is the polar angle (from z-axis, 0 to 180 degrees) and φ is the azimuthal angle (in the xy-plane, 0 to 360 degrees). Some mathematics textbooks swap θ and φ.
Applications
- Physics: Gravitational and electric fields with spherical symmetry.
- Astronomy: Celestial coordinates for star and planet positions.
- Computer Graphics: Camera positioning, environment mapping.
- Navigation: GPS coordinates are a form of spherical coordinates.