---
title: "Prism Deviation calculator — AperiOptic"
description: "Minimum angle of deviation through a prism. Free online optics calculator, with the formula and code snippets."
url: "https://aperioptic.com/calculators/prism-deviation"
---

# Prism Deviation calculator

Minimum angle of deviation through a prism.

Category: [Geometric Optics](https://aperioptic.com/calculators)

Formula: `n = sin((A+δ)/2) / sin(A/2)`

## Inputs

| Input | Parameter | Unit | Default |
| --- | --- | --- | --- |
| Apex A | `A` | ° | 60 |
| Index n | `n` |  | 1.52 |

## Result with the default inputs

- δ min: 38.9284 °

Open it with your own values: put each input in the address as a parameter, for example [`/calculators/prism-deviation?A=60`](https://aperioptic.com/calculators/prism-deviation?A=60). A unit other than the listed one goes in `<parameter>_unit`.

Read more: [Wikipedia: Prism (optics)](https://en.wikipedia.org/wiki/Prism_(optics))

[All optics calculators](https://aperioptic.com/calculators)

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The interactive page: https://aperioptic.com/calculators/prism-deviation (AperiOptic runs in the browser; free, no account). Every page of the site as Markdown: https://aperioptic.com/llms.txt