How to use
- Type a frequency in Value, such as 50.
- Pick From and To: Hz, kHz, MHz, GHz, THz, rev/s, rpm or bpm.
- Read the answer, with the exact factor below it.
How the conversion works
The hertz (Hz) is one cycle per second. Every unit is converted through hertz:
| Unit | In hertz |
|---|---|
| 1 kilohertz (kHz) | 1,000 |
| 1 megahertz (MHz) | 1,000,000 |
| 1 gigahertz (GHz) | 1,000,000,000 |
| 1 revolution per second | 1 |
| 1 revolution per minute (rpm) | 1/60 ≈ 0.0166667 |
| 1 beat per minute (bpm) | 1/60 ≈ 0.0166667 |
Per-minute units divide by 60 because a minute has 60 seconds.
Period and frequency
The period is the time for one cycle: T = 1 ÷ f, and f = 1 ÷ T.
| Frequency | Period |
|---|---|
| 1 Hz | 1 s |
| 50 Hz | 20 ms |
| 60 Hz | 16.67 ms |
| 440 Hz | 2.27 ms |
| 1 kHz | 1 ms |
Examples
- 50 Hz: 50 × 60 = 3,000 rpm
- 7,200 rpm: 7,200 ÷ 60 = 120 Hz
- 72 bpm: 72 ÷ 60 = 1.2 Hz
- 2.4 GHz: 2.4 × 1,000 = 2,400 MHz
Hz and rpm chart
| Hz | rpm |
|---|---|
| 0.5 | 30 |
| 1 | 60 |
| 5 | 300 |
| 10 | 600 |
| 50 | 3,000 |
| 60 | 3,600 |
| 100 | 6,000 |
More detail: angular frequency
- Angular frequency is ω = 2πf, measured in radians per second.
- NIST lists 1 rpm as 0.1047198 rad/s, which is 2π ÷ 60.
- Radians per second measure angle per time, so they are not offered as a unit here.
- NIST’s SI guide uses the hertz only for periodic phenomena.
Working with periods in other time units? Use the time unit converter.