In general, a "C" grade tends to be equivalent to a percentage somewhere in the 70s. There is not one set standard, so it varies among schools. Each institution determines its own grading policies.
For example, at the University of Washington in Seattle, a "C" runs from 75 percent to 79 percent. An 80 is considered a "C" to "C+." At the other end of the scale, 73 or 74 percent is a "C-," while a 72 is a "C" to "D+." Other schools have slightly lower percentages for a "C." At the University of Northern Iowa in Cedar Falls, a "C" is 73 to 76 percent. A "C-" covers 70 to 72, while anything in the high 70s equals a "C+."
