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Free Metric Conversion Calculator — File & Unit Converter Online

Convert 94+ file formats and 345+ metric units instantly in your browser. Free metric conversion calculator with kg to lbs, cm to inches, km to miles and more. No uploads, no tracking, 100% private.

0 conversions completed
Client-side Only
Instant Results
NIST Precision

Your All-in-One Conversion Toolkit

Metric Converter is a free, open-source conversion toolkit that runs entirely in your browser — your files never leave your device.

File conversion between JPG, PNG, WebP, GIF, and more via Canvas API
Unit conversion across 13 categories with NIST SP 811 precision
No accounts, no watermarks, no file size limits
Works offline as a Progressive Web App

How It Works

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1. Choose Your Conversion

Select a file format converter (JPG, PNG, WebP, GIF, MP4, and 90+ more) or a unit converter (length, weight, temperature, and 10+ categories).

2. Convert Instantly

Everything runs in your browser using JavaScript and WebAssembly. No server uploads, no waiting — results appear in milliseconds.

3. Download or Copy

Download your converted file or copy the unit result. All data stays on your device and is deleted when you close the tab.

Metric Converter uses industry-standard tools like FFmpeg.wasm for audio/video processing and Canvas API for image conversion, all running client-side in your browser. Unit conversions follow NIST SP 811 standards with up to 10 decimal places of precision. Whether you need to convert kilometers to miles for a road trip, compress images for your website, or transform video formats for social media — Metric Converter handles it all without compromising your privacy. Available in 9 languages and works offline as a Progressive Web App.

File Converters

Unit Converters

All Unit Categories

Frequently Asked Questions

What is Metric Converter?

Metric Converter is a free online toolkit for file format conversions (JPG, PNG, WebP, GIF, etc.) and unit conversions (length, mass, temperature, and more). It runs entirely in your browser with no server uploads required.

Is my file data safe?

Yes. All file processing happens locally in your browser using client-side JavaScript and WebAssembly. Your files are never uploaded to any server. Once you close the tab, all data is gone.

What conversions are supported?

Metric Converter supports image file conversions between formats like JPG, PNG, WebP, GIF, BMP, TIFF, and AVIF. For units, it covers 10 categories including length, mass, temperature, volume, area, time, speed, energy, pressure, and power.

Do I need to pay?

No. Metric Converter is completely free with no premium tiers, no ads, and no usage limits. It is open-source software.

Can I use it offline?

Yes. Metric Converter is a Progressive Web App (PWA). Install it from your browser and use it anywhere — no internet connection needed.

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