Refractive Index Calculator
Compute refractive index and critical angle from light speeds or Snell law.
Compare Your Options And Get Clear Answers
Compute refractive index and critical angle from light speeds or Snell law.
Refractive Index Estimator
Enter your numbers below for an instant estimate.
How It Works
Key concepts behind this calculator
Enter Values
Fill in each field with your own numbers.
Calculate
Results update as you change the inputs.
Review
Read the breakdown and the explanation.
Adjust
Change values to compare scenarios.
Refractive Quick Guide
Typical values for reference.
| Material | Index | Speed (Mm/s) | Note |
|---|---|---|---|
| Air | 1.000 | 299.7 | Reference |
| Water | 1.333 | 224.9 | Clear |
| Glass | 1.52 | 197.2 | Crown |
| Diamond | 2.417 | 124.0 | High |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
Refractive Index Calculator FAQ
Answers to common questions about this calculator.
The ratio of light speed in a vacuum to its speed in a material.
It gives a quick estimate of refractive index from the values you enter.
No. It is a planning estimate, so check important figures with a professional or official source.
Yes. Edit any field and the result updates when you calculate.