Refractive index to surface reflectance
Type a value in n to get it in % instantly.
4%
That's 1.13× as dense as water, while window glass is 1.01× higher. Light travels 1.5 times slower inside it.
What it means
How much does it bend light?
Index depends on wavelength — that is what makes a prism work. Published values are usually for the yellow sodium line at 589 nm.
The math
How to convert n to %
From the index: the speed inside is c ÷ n, the critical angle is arcsin(1 ÷ n), Brewster’s angle is arctan(n), and the head-on reflectance is ((n − 1) ÷ (n + 1))².
Example: 1.5 n = 4 %.
Every unit
Your index in every unit
Tables
n to % conversion table
| n | % |
|---|---|
| 1.0003 n | 2.249×10⁻⁶ % |
| 1.2 n | 0.826446 % |
| 1.31 n | 1.80094 % |
| 1.33 n | 2.00593 % |
| 1.46 n | 3.4966 % |
| 1.5 n | 4 % |
| 1.6 n | 5.32544 % |
| 1.77 n | 7.7272 % |
| 2 n | 11.1111 % |
| 2.42 n | 17.2395 % |
| 3.4 n | 29.7521 % |
% to n conversion table
| % | n |
|---|---|
| 1.0003 % | 1.22226 n |
| 1.2 % | 1.24604 n |
| 1.31 % | 1.2585 n |
| 1.33 % | 1.26072 n |
| 1.46 % | 1.27487 n |
| 1.5 % | 1.27914 n |
| 1.6 % | 1.28962 n |
| 1.77 % | 1.30692 n |
| 2 % | 1.32943 n |
| 2.42 % | 1.36844 n |
| 3.4 % | 1.45216 n |
Quick answers
Quick answers
- How many % is 1 n?
- 1 n is 0 %.
- How many % is 10 n?
- 10 n is 66.9421 %.
- How many % is 1.5 n?
- 1.5 n is 4 %.
The units
About these units
Refractive index (n)
How many times slower light travels in the material.
Surface reflectance (%)
How much light bounces off a flat surface head-on.
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