| Band | Frequency | Wavelength | Examples |
| Extremely Low Frequency (ELF) | 3 to 30 Hz | 10,000 to 100,000 km | Lightning, Earth's magnetic field |
| Super Low Frequency (SLF) | 30 to 300 Hz | 1,000 to 10,000 km | AC power grids |
| Ultra Low Frequency (ULF) | 300 to 3,000 Hz | 100 to 1,000 km | Submarine communication |
| Very Low Frequency (VLF) | 3 to 30 kHz | 10 to 100 km | Marine navigation, time signals, heart rate monitors |
| Low Frequency (LF) | 30 to 300 kHz | 1 to 10 km | RFID, amateur radio, AM longwave broadcasting |
| Medium Frequency (MF) | 300 to 3,000 kHz | 100 to 1,000 meters | AM radio, amateur radio, avalanche beacons |
| High Frequency (HF) | 3 to 30 MHz | 10 to 100 meters | Shortwave broadcasts, citizens band radio, amateur radio, RFID, radar |
| Very High Frequency (VHF) | 30 to 300 MHz | 1 to 10 meters | FM Radio, television broadcasts, aircraft communications, mobile communications, weather radio |
| Ultra High Frequency (UHF) | 300 to 3,000 MHz | 10 to 100 centimeters | Television broadcasts, microwave ovens, microwave communications, radio astronomy, mobile phones, WiFi, Bluetooth, GPS, FRS radios, GMRS radios, amateur radio, satellite radio, remote control systems |
| Super High Frequency (SHF) | 3 to 30 GHz | 10 to 100 millimeters | Radio astronomy, microwave communications, WiFi, modern radar, communications satellites, satellite television, satellite radio, 5G mobile |
| Extremely High Frequency (EHF) | 30 to 300 GHz | 1 to 10 millimeters | Microwave remote sensing, WiFi |
| Tremendously High Frequency (THF) | 300 to 3,000 GHz | 0.1 to 1 millimeter | Experimental medical imaging to replace X-rays, spectroscopy, remote sensing |
Frequencies vs Wavelength
A frequency indicates how often waves repeat. This is measured in hertz such as Hz, kHz, MHz, GHz and THz. A wavelength indicates the length of each wave. This is measured with metric lengths such as millimeter, meter and kilometer. There is a relationship between frequencies and wavelengths as follows.| Frequency | Wavelength |
| 1 Hz | 299792.5 Kilometers |
| 1 kHz | 299.8 Kilometers |
| 1 MHz | 299.8 Meters |
| 1 GHz | 299.8 Millimeters |
| 1 THz | 299.8 Micrometers |
Frequencies
A hertz represents one cycle per second. This varies by wavelength and the speed of electromagnetic radiation. In a vacuum, electromagnetic radiation moves at the speed of light. The following units are used to represent hertz.| Unit | Cycles Per Second |
| Hertz (Hz) | 1 |
| Kilohertz (kHz) | 1,000 |
| Megahertz (MHz) | 1,000,000 |
| Gigahertz (GHz) | 1,000,000,000 |
| Terahertz (THz) | 1,000,000,000,000 |
| Petahertz (PHz) | 1,000,000,000,000,000 |
| Exahertz (EHz) | 1,000,000,000,000,000,000 |
Allocations
Each nation regulates the use of radio waves by dividing the radio spectrum into regions that are assigned to a purpose or entity. This is unbelievably complex as these aren't standardized from one country to the next and can change with time.
