kilohertz
Frequencyexact by definition
The kilohertz is exactly 1,000 hertz, an exact decimal prefix. It is the band of ultrasonic sensing, switching power supplies, AM radio carriers and audio sampling rates: CD audio samples at 44.1 kHz. The factor is exact by definition.
| 1 | 1,000 |
About the kilohertz
The kilohertz spans the top of hearing and the bottom of radio. Human hearing gives out near 20 kHz, and the ceiling falls with age; dogs hear to roughly 45 kHz, and bats call between about 20 and 100 kHz, which is why bat detectors exist to shift those calls down into our range. AM broadcast carriers sit between about 530 and 1,700 kHz, spaced 10 kHz apart in the Americas and 9 kHz nearly everywhere else. CD audio samples at 44.1 kHz, a little over twice the limit of hearing, which is what sampling theory demands to capture a 20 kHz tone without aliasing.
The number to repeat afterwards is 32.768 kHz. Nearly every quartz watch and real-time clock chip runs its crystal at that frequency because it is exactly Hz: halve it fifteen times with a chain of simple divider stages and precisely one pulse per second comes out the end, no arithmetic circuit required. The tuning-fork crystal cut for that frequency is also small and frugal enough to run for years on a coin cell. On this site the kilohertz feeds the period and wavelength solvers; a 40 kHz ultrasonic cleaner has a period of 25 microseconds, straight from .
One kilohertz in every frequency unit
| 1,000,000,000,000 | nanohertz (nHz) | |
| 31,557,600,000 | per year (1/yr) | |
| 1,000,000,000 | microhertz (μHz) | |
| 86,400,000 | per day (1/d) | |
| 3,600,000 | per hour (1/h) | |
| 1,000,000 | millihertz (mHz) | |
| 60,000 | revolution per minute (rpm) | convert → |
| 60,000 | cycle per minute (cpm) | |
| 60,000 | beat per minute (bpm) | |
| 1,000 | hertz (Hz) | convert → |
| 1,000 | cycle per second (cps) | |
| 1,000 | revolution per second (rev/s) | |
| 1 | kilohertz (kHz)this unit | |
| 0.001 | megahertz (MHz) | convert → |
| 0.000001 | gigahertz (GHz) | |
| 1.00000e-09 | terahertz (THz) | |
| 1.00000e-12 | petahertz (PHz) |