The CPL requires 250 hours of total flight time. These are broken down in cross country hours, pilot in command time etc. Most commercial pilots in the United States will have close to or over 250 hours when they finish.
Flying with a part 141 flight school the hour requirements are a little less. This way you can obtain the CPL at a minimum of 190 hours total time. It is also a requirement that you have completed the instrument rating, or currently enrolled in an instrument rating course.