Spherical Coordinates Calculator

Spherical Coordinates

Convert between Cartesian and Spherical systems

How To Convert Coordinate Systems

Step 1: Identify Current Coordinate System

Determine if you have Cartesian (x, y, z) or Spherical (r, θ, φ) coordinates.

Why: The direction of conversion determines which formulas to apply.

Step 2: Ensure All Three Values Are Known

Verify you have x, y, z (Cartesian) or r, θ, φ (Spherical) values.

Why: 3D space requires three independent values; missing one makes conversion impossible.

Step 3: Check Angle Units

Confirm if angles are in degrees or radians; conversions usually require radians.

Why: Trigonometric functions operate on radians; degree input produces incorrect results.

Step 4: Apply Conversion Formulas

Cartesian-to-Spherical: r = √(x² + y² + z²), θ = atan2(y, x), φ = acos(z/r).

Why: These formulas define the geometric relationships between the two coordinate systems.

Step 5: Verify Results Make Sense Geometrically

Check that r is non-negative and angles fall within expected ranges (0 to 2π for θ, 0 to π for φ).

Why: Out-of-range results indicate calculation errors or unconventional coordinate conventions.

Detailed Example

Scenario: Convert Cartesian point (1, 1, √2) to spherical coordinates.
Step 1 - Identify System: Given Cartesian (x, y, z) = (1, 1, √2).
Step 2 - Verify All Values: x = 1, y = 1, z = 1.414 (all present) ✓
Step 3 - Check Units: Trigonometric functions will output radians.
Step 4 - Apply Formulas: r = √(1² + 1² + 1.414²) = √(1 + 1 + 2) = √4 = 2. θ = atan2(1, 1) = π/4 ≈ 0.785 rad. φ = acos(√2/2) = acos(0.707) ≈ 0.955 rad (or ≈ 54.7°).
Step 5 - Verify: r = 2 > 0 ✓ θ ≈ 0.785 rad is in [0, 2π] ✓ φ ≈ 0.955 rad is in [0, π] ✓
Verification: Distance from origin: √(1 + 1 + 2) = 2 ✓ Angles place point in first octant ✓
Result: Spherical coordinates are r = 2, θ ≈ 0.785 rad, φ ≈ 0.955 rad.
Interpretation: Point is 2 units from origin, 45° in xy-plane, and tilted 54.7° from z-axis.

Definitions

r: Radial distance

θ (theta): Azimuthal angle in the xy-plane

φ (phi): Inclination angle from the z-axis

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