Refractive index (non-magnetic) to relative permittivity (dielectric constant)
Type a value in n to get it in εr instantly.
19.36εr
That's 1.65× as polarizable as silicon, while ethanol is 1.26× higher. A signal in it travels at about 22.73% of the speed of light.
Convert the other way: εr to n
What it means
How strongly does it polarize?
Values are typical at low frequency and room temperature. Water’s permittivity falls sharply at microwave frequencies, which is how microwave ovens heat it.
The math
How to convert n to εr
Absolute permittivity is ε = εr × 8.854 pF/m. For a non-magnetic material the refractive index is √εr, and a cable’s velocity factor is 1 ÷ √εr.
Example: 4.4 n = 19.36 εr.
Every unit
Your permittivity in every unit
Tables
n to εr conversion table
| n | εr |
|---|---|
| 1 n | 1 εr |
| 1.5 n | 2.25 εr |
| 2 n | 4 εr |
| 2.1 n | 4.41 εr |
| 3 n | 9 εr |
| 4 n | 16 εr |
| 4.4 n | 19.36 εr |
| 6 n | 36 εr |
| 10 n | 100 εr |
| 20 n | 400 εr |
| 50 n | 2,500 εr |
| 80 n | 6,400 εr |
εr to n conversion table
| εr | n |
|---|---|
| 1 εr | 1 n |
| 1.5 εr | 1.22474 n |
| 2 εr | 1.41421 n |
| 2.1 εr | 1.44914 n |
| 3 εr | 1.73205 n |
| 4 εr | 2 n |
| 4.4 εr | 2.09762 n |
| 6 εr | 2.44949 n |
| 10 εr | 3.16228 n |
| 20 εr | 4.47214 n |
| 50 εr | 7.07107 n |
| 80 εr | 8.94427 n |
Quick answers
Quick answers
- How many εr is 1 n?
- 1 n is 1 εr.
- How many εr is 10 n?
- 10 n is 100 εr.
- How many εr is 4.4 n?
- 4.4 n is 19.36 εr.
The units
About these units
Refractive index (non-magnetic) (n)
The square root of εr at the same frequency.
Relative permittivity (dielectric constant) (εr)
Compared with a vacuum, which is exactly 1.
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