21 megahertz (21 MHz)
21 megahertz equals 21,000,000 hertz, 0.021 gigahertz, 21,000 kilohertz and 1,260,000,000 revolutions per minute.
21 megahertz = 21,000,000 hertz
What 21 megahertz means in practice
21 megahertz sits between AM radio (1 MHz) and FM radio (100 MHz).
- A resting human heartbeat: 0.0000012 MHz
- The lowest note humans can hear: 0.00002 MHz
- European mains electricity: 0.00005 MHz
- North American mains electricity: 0.00006 MHz
- Middle C on a piano: 0.00026163 MHz
- The tuning note A4: 0.00044 MHz
- The highest note humans can hear: 0.02 MHz
- AM radio: 1 MHz
- FM radio: 100 MHz
- A microwave oven: 2,450 MHz
- 5 GHz Wi-Fi: 5,000 MHz
- Visible red light: 430,000,000 MHz
- Visible violet light: 750,000,000 MHz
21 megahertz in all frequency units
| Unit | Value | Scientific notation |
|---|---|---|
| Hertz (Hz) | 21,000,000 | 2.1 × 107 |
| Gigahertz (GHz) | 0.021 | 2.1 × 10-2 |
| Kilohertz (kHz) | 21,000 | 2.1 × 104 |
| Revolutions per minute (rpm) | 1,260,000,000 | 1.26 × 109 |
| Beats per minute (bpm) | 1,260,000,000 | 1.26 × 109 |
| Terahertz (THz) | 0.000021 | 2.1 × 10-5 |
| Cycles per second (cps) | 21,000,000 | 2.1 × 107 |
| Revolutions per second (rps) | 21,000,000 | 2.1 × 107 |
| Cycles per minute (cpm) | 1,260,000,000 | 1.26 × 109 |
| Per minute (min⁻¹) | 1,260,000,000 | 1.26 × 109 |
| Per second (s⁻¹) | 21,000,000 | 2.1 × 107 |
| Millihertz (mHz) | 21,000,000,000 | 2.1 × 1010 |
| Per day (d⁻¹) | 1,814,400,000,000 | 1.8144 × 1012 |
| Per hour (h⁻¹) | 75,600,000,000 | 7.56 × 1010 |
| Petahertz (PHz) | 2.1 × 10-8 | 2.1 × 10-8 |
| Per week (wk⁻¹) | 12,700,800,000,000 | 1.27008 × 1013 |
| Per year (a⁻¹) | 662,695,992,000,000 | 6.62696 × 1014 |
| Exahertz (EHz) | 2.1 × 10-11 | 2.1 × 10-11 |
| Cycles per day (cpd) | 1,814,400,000,000 | 1.8144 × 1012 |
| Cycles per hour (cph) | 75,600,000,000 | 7.56 × 1010 |
| Microhertz (µHz) | 21,000,000,000,000 | 2.1 × 1013 |
| Planck frequencies (ωP) | 1.1321621 × 10-36 | 1.13216 × 10-36 |
| Fresnels (fresnel) | 0.000021 | 2.1 × 10-5 |
Other amounts of megahertz
About the megahertz
The megahertz is a million hertz. It is used for FM radio (88–108 MHz), TV and older computer clock speeds. Read more about megahertz.