CCUnits is a program for Windows 95/ 98/ ME/ 2000/ NT to convert units of measure common in engineering and science. Also, several physical constants can be consulted. It includes 56 magnitudes and in each magnitude the most frequently used units have been chosen. Unlike other unit conversion programs, CCUnits doesn't overwhelm the user with hundreds of units and magnitudes, it only provides the most frequently used and important ones. The use of the program is easy and intuitive. With a few clicks, the user can perform unit conversions, and access a list of physical constants. Results can be displayed in normal and scentific formats, and the user can specify the number of decimal places.