---
title: "Étendue / AΩ Product calculator — AperiOptic"
description: "Conserved geometrical extent of a beam. Free online optics calculator, with the formula and code snippets."
url: "https://aperioptic.com/calculators/etendue-a-omega-product"
---

# Étendue / AΩ Product calculator

Conserved geometrical extent of a beam.

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

Formula: `G = π·A·sin²θ`

## Inputs

| Input | Parameter | Unit | Default |
| --- | --- | --- | --- |
| Area | `A` | mm² | 10 |
| Half-angle | `th` | ° | 10 |

## Result with the default inputs

- Étendue: 0.9473 mm²·sr

Open it with your own values: put each input in the address as a parameter, for example [`/calculators/etendue-a-omega-product?A=10`](https://aperioptic.com/calculators/etendue-a-omega-product?A=10). A unit other than the listed one goes in `<parameter>_unit`.

Read more: [Wikipedia: Etendue](https://en.wikipedia.org/wiki/Etendue)

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

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