Reflection Coefficient Calculator

Solve reflections for optics, RF, acoustics, and cables. Choose models, enter values, and compute instantly. Download CSV or PDF and keep your records organized.

Calculator

Pick the scenario that matches your boundary problem.
Indices are typical for optics; impedances for waves and acoustics.
Use 0 for purely real impedance.
Incidence angle from the surface normal.
Inductive loads use +jX; capacitive loads use −jX.

Example Data Table

Scenario Inputs Output highlights
Normal (indices) n₁=1.00, n₂=1.50 r≈−0.200, R≈0.040 (4% power)
Fresnel (30°) n₁=1.00, n₂=1.50, θᵢ=30° Different rₛ and rₚ; Rs and Rp differ
Transmission line Z₀=50Ω, Zᴸ=75Ω |Γ|≈0.200, VSWR≈1.50
These are typical values to validate your setup and units.

Formula Used

  • Normal incidence (indices): r = (n₁ − n₂)/(n₁ + n₂), reflectance R = |r|².
  • Normal incidence (impedance): r = (Z₂ − Z₁)/(Z₂ + Z₁), reflectance R = |r|².
  • Fresnel coefficients: Use Snell’s law n₁ sinθᵢ = n₂ sinθₜ. Then rₛ = (n₁ cosθᵢ − n₂ cosθₜ)/(n₁ cosθᵢ + n₂ cosθₜ), rₚ = (n₂ cosθᵢ − n₁ cosθₜ)/(n₂ cosθᵢ + n₁ cosθₜ).
  • Transmission line: Γ = (Zᴸ − Z₀)/(Zᴸ + Z₀), VSWR = (1+|Γ|)/(1−|Γ|) for |Γ|<1.
For lossy or complex media, impedance form is often more appropriate.

How to Use This Calculator

  1. Select a model: normal incidence, Fresnel, or transmission line.
  2. Enter values in consistent units (Ω for impedances, degrees for angles).
  3. Click Calculate to display results under the header.
  4. Review magnitude, phase, and power reflectance for interpretation.
  5. Use Download CSV or Download PDF to save outputs.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.