Hertz to RPM Converter
Free Hertz rpmconverter Converter for signal & frequency units. Enter a value to see equivalent measurements across systems.
Reviewed by Manoj Kumar, Mathematics Educator
Formula
RPM = Hertz * 60 | Hertz = RPM / 60
Multiply hertz by 60 to get RPM since there are 60 seconds per minute. For motor synchronous speed, use RPM = (120 * f) / poles. Angular velocity in rad/s equals 2 * pi * frequency in Hz.
Worked Examples
Example 1: European Power Motor Speed
Problem:A 4-pole motor operates on 50 Hz European power. What is its synchronous speed?
Solution:Rotational frequency: 50 Hz = 50 * 60 = 3,000 RPM\nSynchronous speed = (120 * 50) / 4 = 1,500 RPM\nAngular velocity = 2 * pi * 50 = 314.16 rad/s
Result:50 Hz 4-pole motor: 1,500 RPM synchronous speed
Example 2: Hard Drive Spindle Speed
Problem:A hard drive spins at 7,200 RPM. What is the frequency in hertz?
Solution:Frequency = RPM / 60\nf = 7,200 / 60 = 120 Hz\nPeriod = 1 / 120 = 0.00833 seconds\nAngular velocity = 2 * pi * 120 = 753.98 rad/s
Result:7,200 RPM = 120 Hz (period of 8.33 ms per revolution)
Frequently Asked Questions
How do you convert hertz to RPM?
To convert hertz to RPM (revolutions per minute), multiply the frequency in hertz by 60. This works because hertz measures cycles per second and there are 60 seconds in a minute. For example, 50 Hz equals 50 * 60 = 3,000 RPM. Conversely, to convert RPM to hertz, divide the RPM value by 60. A motor spinning at 1,800 RPM has a rotational frequency of 1,800 / 60 = 30 Hz.
References
Reviewed by Manoj Kumar, Mathematics Educator · Editorial policy