---
title: "Magnification (Optical) calculator — AperiOptic"
description: "Linear magnification from image and object heights. Free online optics calculator, with the formula and code snippets."
url: "https://aperioptic.com/calculators/magnification-optical"
---

# Magnification (Optical) calculator

Linear magnification from image and object heights.

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

Formula: `m = hi/ho = -di/do`

## Inputs

| Input | Parameter | Unit | Default |
| --- | --- | --- | --- |
| Object h | `ho` | mm | 10 |
| Image dist | `di` | mm | 200 |
| Object dist | `do` | mm | 100 |

## Result with the default inputs

- Magnification: -2×
- Image height: -20 mm

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

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

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