MihsabaShare this free calculator
Send this tool to someone who needs the calculation.
How to use
This online frequency converter changes Hz, kHz, MHz, GHz, THz, RPM, RPS, rad/s and BPM, and also converts cycle period to frequency with f=1/T. For RPM to Hz divide by 60; 3,000 RPM equals 50 Hz. For period to hertz, convert the period to seconds first: 10 ms is 0.01 s, so the frequency is 100 Hz.
- Enter a frequency/rate value, or a positive cycle period when using a period unit.
- Choose source and target units, including hertz-based units, rotational rates or cycle-period units.
- Calculate to see the target value plus Hz, kHz, RPM, rad/s and the equivalent period.
How it is calculated
Example
Example: 3,000 RPM = 50 Hz = 0.05 kHz ≈ 314.15926536 rad/s, and a 50 Hz cycle has a 0.02 s period. Likewise 2.4 GHz = 2,400 MHz.
Important notes
Hz counts complete cycles per second, while rad/s measures angular change, so 1 Hz = 2π rad/s rather than 1 rad/s. RPM, BPM and CPM share the same numerical per-minute conversion when one event corresponds to one cycle, but their physical meaning differs. T=1/f is unbounded at f=0, shown as ∞.
Worked examples and interpreting results
Frequency counts cycles per second; period measures the duration of one cycle. Their relationship is reciprocal: a 20 millisecond period means 50 cycles per second.
| Case | Calculation | Result |
|---|---|---|
| A 20 millisecond period | 1 ÷ (20 ÷ 1000) | 50 Hz |
| 3000 revolutions per minute | 3000 ÷ 60 | 50 Hz |
How to check the result
Hz and MHz scale linearly, but converting between period and frequency requires the reciprocal. A zero period cannot represent a cycle with finite frequency.
RPM to RPS, hertz, rad/s and cycle period
Divide revolutions per minute (RPM) by 60 to obtain revolutions per second (RPS). A periodic rotational frequency of one RPS corresponds to one hertz. Angular speed in rad/s is frequency in Hz multiplied by 2π.
- 120 RPM to RPS: 120 ÷ 60 = 2 RPS
- Cycle period at 2 Hz: 1 ÷ 2 = 0.5 s
- Angular speed at 60 RPM: 2 × π × (60 ÷ 60) = ≈ 6.28319 rad/s
Important distinction
Hz measures cycles per second, while rad/s measures angular change per second. Use the 2π factor when converting and apply period = 1/f only for positive frequency.
Related calculators
Frequently asked questions
How do I convert a period to hertz?
Use f = 1/T. If the period T is in seconds, the result is in hertz; for example, 0.02 s corresponds to 50 Hz.
How do I convert RPM to Hz?
Divide RPM by 60; for example 3,600 RPM = 60 Hz.
What is the difference between Hz and rad/s?
Hz counts cycles per second; rad/s is angular frequency, with ω=2πf.
Is GHz 1,000 times MHz?
Yes. 1 GHz = 1,000 MHz = 1,000,000 kHz = 1,000,000,000 Hz.
How do I convert RPS to RPM?
Multiply revolutions per second by 60. For example, 25 RPS equals 1,500 RPM. Converting rotation to linear speed also requires a radius or circumference.
How many RPS and hertz are 3,000 RPM?
Divide revolutions per minute by 60: 3,000 RPM ÷ 60 = 50 revolutions per second (RPS), equivalent to 50 Hz for one complete cycle per revolution. Angular speed is 2π × 50 = 100π rad/s.
How do I convert period in milliseconds to frequency in hertz?
First convert the period from milliseconds to seconds by dividing by 1,000. Then compute f = 1/T. A period of 10 ms is 0.01 s, so f = 100 Hz. This reciprocal rule requires a strictly positive period.