Local · Private · Free

Unit Converter

8 unit categories including length, weight, temperature, area, volume, speed, storage and time. Converted live as you type, entirely on your device.

From

Calculated locally, nothing is sent anywhere.

Common length conversions

Quick reference

Accurate conversions, fully offline

Every factor here is exact (the inch is defined as 25.4 mm, a mile as 1609.344 m, and so on), and temperatures use the proper offset formulas, not naive multiplication. It all runs in your browser, so it works on a plane with no signal and never sends a thing.

About Unit Converter

Unit Converter is a free, private tool by Digital Heroes that converts across 8 categories: length, weight, temperature, area, volume, speed, digital storage, and time. Every conversion runs entirely in your browser, nothing is uploaded, no sign-up is needed, and it works offline. Results update live as you type in either field, so you can also reverse-convert by entering the output value. All factors use exact defined values (for example, 1 inch = 25.4 mm exactly), and temperature conversions use the correct offset formulas, not naive multiplication.

What you can do

Convert length between millimeters, centimeters, meters, kilometers, inches, feet, yards, miles, and nautical miles.

Convert weight and mass across milligrams, grams, kilograms, metric tonnes, ounces, pounds, stone, and US or UK tons.

Convert temperature between Celsius, Fahrenheit, and Kelvin using correct offset formulas.

Convert area, volume, and speed including acres, hectares, US cups, gallons, knots, and more.

Convert digital storage between bits, bytes, KB, MB, GB, TB, and their binary equivalents (KiB, MiB, GiB, TiB).

Reverse-convert by typing in the output field: the input updates automatically.

How to use Unit Converter

Pick a category from the tabs (Length, Weight, Temperature, and so on).

Type a value in the From field and choose your source unit from the dropdown.

Choose your target unit in the To dropdown. The result appears instantly.

Use the swap button to reverse direction, or type directly in the result field to convert the other way.

Frequently asked questions

Is Unit Converter free?

Yes, Unit Converter is completely free for everyone. No sign-up, no account and no usage limits.

Is it private? Are my files uploaded anywhere?

No. Unit Converter runs entirely in your browser on your own device, so your data never leaves your computer and nothing is uploaded to a server.

Does it work offline?

Yes. This tool is a Progressive Web App, once the page has loaded it keeps working offline, and you can install it as an app from your browser.

Do I need to install anything or create an account?

No. Just open the page and start using it. Installing it as an app is optional and only adds offline convenience.

What does Unit Converter do?

It converts values across 8 unit categories: length, weight, temperature, area, volume, speed, digital storage, and time. Pick a category, enter a value and choose your units, and the result updates instantly. You can also type in the output field to reverse-convert. All calculations run locally in your browser with no data sent anywhere.