# How to Calculate Refractive Index

How do you calculate Refractive Index?

## Refractive Index Calculation

Refractive index is the measurement of ratio of speed of light in a vacuum to the measurement of speed of light in a material. The amount of refraction of the light can be calculated on two aspects.

The angle at which the light hits the boundaries. Relative densities difference between the two objects, which helps to determine the speed of light.

**Formula**

**Refractive Index = sin i / sin r**

Where,

i - angle of incidence

r - angle of refraction

**Steps for Refractive Index Calculation**

Step 1: Consider, a light ray hits on a object, at this point the angle of incidence is 70 degrees and angle of refraction is 45 degrees. Find the refractive index.

Angle of Incidence (i) = 70 degrees

Angle of Refraction (r) = 45 degrees

**Step 2:** Substitute the values in the formula

Refractive Index = sin i / sin r

= sin 70 / sin 45

= 0.77 / 0.85

Refractive Index = **0.905**

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