Frequency Converter
Convert hertz, kHz, MHz, GHz, and rpm.
Enter a value, choose the units, and see the result plus every other frequency unit.
Revolutions per minute → Hertz
Frequency Converter
Convert frequency and rotation speed between millihertz, hertz, kilohertz, megahertz, gigahertz, terahertz, revolutions per minute, revolutions per second, beats per minute, radians per second, and degrees per second. It links the language of electronics (Hz), mechanics (rpm), music (bpm), and physics (rad/s).
One cycle per second
Every unit here counts repeating events per unit of time. The hertz is one cycle per second; everything else is a scaled version:
| Unit | Hertz |
|---|---|
| 1 rpm | 1/60 ≈ 0.01667 |
| 1 bpm | 1/60 ≈ 0.01667 |
| 1 rps | 1 |
| 1 rad/s | 1/(2π) ≈ 0.15915 |
| 1 °/s | 1/360 ≈ 0.00278 |
| 1 kHz | 1,000 |
| 1 GHz | 1,000,000,000 |
Where you meet each unit
- Electronics and radio: FM stations broadcast around 88–108 MHz, Wi-Fi uses 2.4 GHz and 5 GHz, and CPUs run at several GHz.
- Audio: human hearing spans roughly 20 Hz to 20 kHz; concert pitch A is 440 Hz.
- Music tempo: 120 bpm is exactly 2 Hz – two beats every second.
- Mechanics: motors, fans, and drives are rated in rpm. A 7,200 rpm hard disk spins at 120 Hz.
- Physics and control systems: angular velocity is written in rad/s; 1 Hz is 2π rad/s.
Worked example
A fan datasheet lists 1,500 rpm. Select Revolutions per minute, enter 1500, and read 25 Hz, 157.08 rad/s, or 9,000 °/s.
Frequency and period
The period is the inverse of frequency: a 50 Hz mains supply repeats every 20 ms. To express periods in other time units, use the Time Converter. For turning angles into other units, see the Angle Converter.
Frequently Asked Questions
How do I convert rpm to Hz?
Divide by 60. An engine idling at 900 rpm turns 15 times per second (15 Hz); a hard drive spinning at 7,200 rpm runs at 120 Hz.
What is the relation between Hz and rad/s?
Angular frequency ω = 2π × f, so 1 Hz equals about 6.2832 rad/s. The converter treats radians per second as a rotation rate for that reason.
How many MHz are in a GHz?
One gigahertz is 1,000 megahertz or one billion hertz. A 2.4 GHz Wi-Fi band is 2,400 MHz.