How to use the frequency converter
- Type the number in Value. The default is 3,000.
- Choose its unit in From, for example rpm (revolutions per minute).
- Choose the target in To, for example Hz. The answer appears at once.
- Below the result you get a table of all 11 units and a Period (1/f) line in seconds.
What it does and when to use it
Frequency means “how many times per second”. Engineers, musicians and doctors count it in different ways. A motor plate gives rpm, a physics formula wants rad/s, a radio dial shows MHz, a metronome shows bpm and a CPU spec shows GHz. This converter connects all of them through hertz.
Typical uses: turning an engine or fan speed into Hz to check against mains frequency or a vibration reading, getting ω in rad/s for a rotating-body formula, or finding how long one beat lasts at a given tempo. To hear a frequency, try the tone generator. To find the tempo of a song first, use the BPM detector. For the wavelength of a radio or light frequency, use the frequency to wavelength converter.
How it works
Each unit is stored as a number of hertz.
| Unit | Hz |
|---|---|
| rpm, beats per minute | 1/60 |
| revolutions per hour | 1/3,600 |
| degrees per second | 1/360 |
| rad/s | 1/(2π) ≈ 0.159155 |
| mHz | 0.001 |
| kHz, MHz, GHz, THz | 10³, 10⁶, 10⁹, 10¹² |
The tool multiplies by the From factor, divides by the To factor and shows 12 significant figures. The period is 1 ÷ (value in Hz). Only rad/s depends on π; every other factor is exact.
Worked examples
A spinning hard drive. 7,200 rpm = 120 Hz. The tool also shows Period (1/f): 0.008333333333 s, so one turn takes about 8.3 ms.
A tempo. 120 beats per minute = 2 Hz. The period is 0.5 s, so each beat is half a second apart.
Angular speed from a physics problem. 100 rad/s = 954.929658551 rpm, or 15.9154943092 Hz.
Limits and tips
- Period is hidden for zero or negative values, because 1 ÷ 0 has no meaning.
- rad/s here is an angular frequency. If you need an angle itself (degrees or radians), use the angle converter.
- For time units on their own (ms, minutes, hours), the time converter is quicker.
- Results below 10⁻⁹ switch to scientific notation. For 7,200 rpm the THz row shows 1.2e-10.
Frequently asked questions
How do I convert rpm to Hz?
Why is 1 Hz equal to 6.28 rad/s and not 1 rad/s?
What is the period?
Is beats per minute the same as rpm?
What is the difference between mHz and MHz?
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