Search Ctrl K
Home / Tools
THE FEUTEX TOOLKIT

Refraction and Total Internal Reflection

Calculate the critical angle for a ray crossing from higher to lower refractive index.

Photography workspace● Runs in your browser
01 Your input
02 Your result
View or copy raw result data
FormulaCritical angle = asin(n2/n1)*180/PI; Brewster angle = atan(n2/n1)*180/PI
Sources and model references

Worked example

Inputs

Incident-medium index
1.5
Exit-medium index
1

Expected results

Critical angle
41.8103149 degrees
Brewster angle
33.69006753 degrees

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Calculate the critical angle for a ray crossing from higher to lower refractive index.
  2. Set incident-medium index, exit-medium index in the indicated units.
  3. Calculate and compare critical angle, brewster angle.

Try this example

{
  "n1": 1.5,
  "n2": 1
}

Accuracy and scope

Idealized educational model. Enter measured values in the displayed units; real systems may require additional corrections.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.