Cool Ruler is a program ruler for determination of the extent of objects on the monitor. With its help it is possible to measure any screen objects. Measurements are taken in pixels, centimeters, inches or in arbitrary units. The scale of a scale can be changed randomly, and also to do on it necessary marks. For facilitation of operation the calculator is built in the program. Also you can change appearance of the program and use at the same time some rulers on the monitor.