๐ถ Frequency Converter
Convert between hertz (Hz), kilohertz, megahertz, gigahertz, and rpm (revolutions per minute) in real time. Useful for checking radio equipment frequencies or converting motor and engine rotational speeds.
How to use
- Enter a value into any frequency unit field (Hz, kHz, MHz, GHz, or rpm).
- The converted values appear instantly in the other unit fields.
How the calculation works
Frequency is how many times something repeats per second, measured in hertz (Hz). 1 Hz is once a second, 1 kHz a thousand times, 1 MHz a million and 1 GHz a billion. rpm (revolutions per minute) counts rotations per minute, so dividing by 60 gives rotations per second โ hertz. A motor spinning at 3,000 rpm turns 50 times a second, 50 Hz. The reciprocal of frequency is the period, the time one cycle takes. For radio waves, dividing the speed of light by the frequency gives the wavelength: 2.4 GHz Wi-Fi has a period of about 0.42 nanoseconds and a wavelength of about 12.5 cm.
Worked example
A motor at 3,000 rpm in hertz 3,000 รท 60 = 50 Hz That matches the 50 Hz mains frequency of eastern Japan. Some AC motors turn in step with the supply frequency, which is why their speed differs between eastern Japan and western Japan (60 Hz). 2.4 GHz is 2,400 MHz, or 2,400,000 kHz.
Things to be aware of
- The rpmโHz conversion counts revolutions or cycles. Angular velocity (rad/s) differs by a factor of 2ฯ.
- CPU clock speed is one indicator of performance, but different generations and designs perform differently at the same frequency.
- To relate frequencies to musical pitch, the note frequency chart is more convenient.
- For period or wavelength, take the reciprocal or divide the speed of light by the frequency separately.
FAQ
What's the relationship between rpm and Hz?
1 rpm (one revolution per minute) equals 1/60 Hz. This lets you convert a motor's rotational speed into a frequency in Hz.
Can I use this for Wi-Fi or CPU clock speeds?
Yes โ it's useful for comparing a GHz CPU clock speed or radio frequency against other units.
Can I use this for musical pitch frequencies?
The Hz conversion itself works, but to find the matching note name, try our Note Name & Frequency Chart.