JSUC Instructions

The JavaScript Unit Converter is a JavaScript unit conversion utility that I wrote back in 1998. It's a small (20KB), fast, self-enclosed, completely customizable script file that can be downloaded and run locally. JSUC can convert between several different units (approx. 250!) in a number of physical properties: it can convert between Celsius and Fahrenheit, inches and meters, mph and kph and a lot of other esoteric units you've probably never heard of.

Run JSUC Now!

How to use it

When you load up JSUC (by selecting the JS Unit Converter link on the top right of this page --go ahead and do it now), you'll get three drop down menus: 1) a menu labeled "Property", 2) one labeled "A", and 3) another labeled "B". The "Property" menu lists all the different properties written in JSUC; it defaults to the first one, usually 'Acceleration', but you can select anyone you wish by dropping down the menu. When you select a property, the options in the "A" and "B" menus are automatically updated to the supported units of the selected property.

Say you want to convert 75 mph (the most common US highway speed limit) to kph:
  1. Select 'Velocity & Speed' from the "Property" menu: Both "A" and "B" menus default to 'Meter/Second (m/sec)'.
  2. Select 'Mile (US)/hour (mph)' in menu "A" (you could use B, it doesnt really matter).
  3. Select 'Kilometer/hour (kph)' in menu "B".
  4. Plug '75' (no quotes) in the input box next to menu "A".
  5. Hit the button 'Convert to B' which is next to the box you entered '75' in.
You should get something approximately equal to 120.709 kph (depending on the accuracy of the machine you are using).

Local Use and Reference Data

JSUC is written to be self-enclosed and autonomous: you can download it to your hard disk or UNIX account and use it from your own browser. You can do that by right-clicking (or holding down the mouse button for Macs) on the JS Unit Converter link on any JSUC page and select "Save Link As..." or something else to that effect. Then, by using the File menu command for opening a local file (depending on your browser) you can run your local copy.

The "Reference Data" link will supply you with some handy constants and other frequently used numbers in a number of fields.


I wrote JSUC as an exercise in JavaScript: It's not perfect nor can it not be done better. I just think it's a nifty thing to have around, especially if you are an engineer or a scientist, stuck on an obscure unit and all you've got is some high-end workstation where no-one bothered to write a utility like this.

Because JSUC is essentially a big script, all the source code is there for anyone to see; you are free to do what you want with it: change it, deface it, customize it, add to it. If you do, please read the comments in the actual file to guide you and give me a credit somewhere!

If you're curious, JSUC is based on an earlier utility of mine, Total Control Converter for Windows 3.1

If you find anything wrong with JSUC, or have any suggestions or comments, feel free to .