---
title: "Length / Distance calculator — AperiOptic"
description: "Convert between common optical length units. Free online optics calculator, with the formula and code snippets."
url: "https://aperioptic.com/calculators/length-distance"
---

# Length / Distance calculator

Convert between common optical length units.

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

Formula: `1 in = 25.4 mm · 1 mil = 25.4 µm`

## Inputs

| Input | Parameter | Unit | Default |
| --- | --- | --- | --- |
| Length | `x` | mm | 25.4 |

## Result with the default inputs

- Meters: 0.0254 m
- Centimeters: 2.54 cm
- Millimeters: 25.4 mm
- Micrometers: 25400 µm
- Inches: 1 in
- Mils: 1000 mil

Open it with your own values: put each input in the address as a parameter, for example [`/calculators/length-distance?x=25.4`](https://aperioptic.com/calculators/length-distance?x=25.4). A unit other than the listed one goes in `<parameter>_unit`.

Read more: [Wikipedia: Conversion of units, Length](https://en.wikipedia.org/wiki/Conversion_of_units#Length)

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

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