PWM frequency library

RichMo:
I made a 1Hz to 2MHz Adjustable frequency PWM library for Arduino. Maybe this will help you.
http://www.rmcybernetics.com/projects/code/index.htm

Hi, I have seen your PWM library.
What I don't fully onderstand is how to use the pulsewidth.
If I have a frequency of 75Hz, what should the pulsewidth be for 50% dutycycle?
75Hz is 13,33 msec, so 50% is 6,67 msec, so pulsewidth should be about 6666667 nsec?