Frequency Converter
Converters · Added 15 August 2026
Convert frequency between the SI hertz family, rotational units like RPM and radians per second, and beats per minute. The one to be careful with is radians per second: that is angular frequency, and it differs from hertz by a factor of 2π rather than being a simple rename.
Result
1 MHz in hertz
1,000,000 Hz
1 MHz = 1,000,000 Hz
The same value in every unit
- Hertz (Hz)
- 1,000,000
- Millihertz (mHz)
- 1,000,000,000
- Kilohertz (kHz)
- 1,000
- Megahertz (MHz)
- 1
- Gigahertz (GHz)
- 0.001
- Terahertz (THz)
- 0.000001
- Revolution per minute (rpm)
- 60,000,000
- Revolution per second (rps)
- 1,000,000
- Radian per second (rad/s)
- 6,283,185.31
- Degree per second (°/s)
- 360,000,000
- Beat per minute (BPM)
- 60,000,000
Radians per second is angular frequency, not the same number as hertz — they differ by a factor of 2π, because one cycle is 2π radians. Revolutions per minute and beats per minute are both simply hertz divided by sixty.
How to use the frequency converter
- 1Enter the frequency value you have.
- 2Choose the unit it is in and the unit you want.
- 3Remember that rad/s is angular frequency — 2π times the value in hertz.
- 4The reference table shows every unit at once.
- 5Swap the units to reverse the direction.
Examples
Engine speed
- Input
- 3,000 rpm
- Result
- 50 Hz · 314.16 rad/s
Fifty revolutions a second — which is also why a 50 Hz generator turns at 3,000 rpm on a two-pole machine.
Processor clock
- Input
- 3.6 GHz
- Result
- 3,600 MHz · 3.6 × 10⁹ Hz
Three point six billion cycles a second.
Music tempo
- Input
- 120 BPM
- Result
- 2 Hz
Two beats a second. BPM and RPM are numerically identical — both are per-minute counts.
About the frequency converter
One unit spanning an extraordinary range
Frequency is one of the few quantities where a single unit stretches across more than twenty orders of magnitude in everyday use. A pendulum swings at around 1 Hz, mains electricity alternates at 50 or 60, audible sound spans roughly 20 Hz to 20 kHz, radio runs from kilohertz to gigahertz, and visible light sits in the hundreds of terahertz.
The hertz replaced the older and more descriptive 'cycles per second' in 1960, honouring Heinrich Hertz, who first demonstrated electromagnetic waves experimentally. Older equipment and documentation still carry the abbreviation c/s or cps, meaning exactly the same thing.
Because the range is so wide, prefixes do most of the work. Getting a prefix wrong is a factor of a thousand, which is usually obvious in context — a 3 kHz processor or a 3 GHz pendulum announce themselves as errors. Where it genuinely bites is in the middle of the range, where both readings are plausible.
Rotational speed, and why it matters where you measure it
Revolutions per minute is the practical unit for anything that spins, from engines to hard drives to washing machine spin cycles. Converting to hertz is a division by sixty, and converting to radians per second means multiplying by 2π after that — the step most often skipped when a specification in RPM meets a formula expecting ω.
The connection between rotational speed and electrical frequency is direct in generators and motors. A two-pole alternator turning at 3,000 rpm produces 50 Hz; a four-pole machine produces the same 50 Hz at 1,500 rpm. This is why generator sets for 60 Hz markets run at 3,600 or 1,800 rpm instead, and why an induction motor's nameplate speed is always slightly below these round figures — the slip is what makes it produce torque.
For vibration work the same units carry a different weight. Machinery faults show up as characteristic frequencies related to shaft speed, so a vibration spectrum is usually plotted in orders — multiples of running speed — rather than in hertz. Converting between the two requires knowing the shaft's RPM at the moment of measurement, which is why vibration data is meaningless without it.