Frequency Converter
Convert frequency between hertz, kilohertz, megahertz, gigahertz, terahertz, and RPM.
How to use this tool
- Enter frequency and from unit in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your kilohertz and the full breakdown beneath it.
Formula
All frequencies are normalised to hertz (Hz), then converted to each output unit:
Hz = value × factorfrom
Factors: 1 kHz = 1,000 Hz, 1 MHz = 1,000,000 Hz, 1 GHz = 1,000,000,000 Hz, 1 THz = 1,000,000,000,000 Hz, 1 RPM = 1/60 Hz ≈ 0.01667 Hz.
How it works
The converter uses hertz (cycles per second) as its base. The input is multiplied by its Hz-equivalent factor to produce a raw Hz count, which is then divided by each output unit's factor. RPM is included because rotating machinery is often rated in revolutions per minute, and 1 RPM corresponds to exactly 1/60 Hz.
Common mistake: Confusing RPM with Hz when working with motors or audio equipment. A motor spinning at 3,000 RPM produces a fundamental frequency of 50 Hz — if you treat 3,000 as directly in Hz you will overestimate the frequency by a factor of 60, leading to errors in vibration analysis or drive selection.
Worked example
Convert 1 MHz to all frequency units
- Input: 1 MHz. Factor = 1,000,000 Hz.
- Base Hz = 1 × 1,000,000 = 1,000,000 Hz.
- kHz = 1,000,000 / 1,000 = 1,000; GHz = 1,000,000 / 1,000,000,000 = 0.001; THz = 1 × 10⁻⁶.
- RPM = 1,000,000 / (1/60) = 1,000,000 × 60 = 60,000,000.
1 MHz = 1,000,000 Hz = 1,000 kHz = 0.001 GHz = 0.000001 THz = 60,000,000 RPM.
Common mistakes to avoid
- Confusing Hz (cycles per second) with RPM (revolutions per minute) without converting -- 60 RPM = 1 Hz; applying an RPM value directly to a formula expecting Hz gives a 60x error.
- Treating audio frequencies in kHz as if they were in MHz -- a 20 kHz hearing limit is 0.02 MHz, not 20 MHz; the distinction matters when reading RF specifications.
- Forgetting that terahertz (THz) describes infrared and optical light frequencies -- 300 THz is visible red light, which differs fundamentally from a 300 GHz microwave.
Key terms
- Hertz (Hz)
- The SI unit of frequency, equal to one cycle (or event) per second. Named after physicist Heinrich Hertz.
- Megahertz (MHz)
- One million hertz. Used to describe radio frequencies, CPU clock speeds, and memory bus speeds.
- Gigahertz (GHz)
- One billion hertz. Modern processor cores are rated in GHz; consumer Wi-Fi operates at 2.4 GHz and 5 GHz.
- RPM (Revolutions Per Minute)
- The number of complete rotations made per minute. Common in mechanical engineering and motor specifications. Converted to Hz by dividing by 60.
Frequently asked questions
- What frequency range can humans hear?
- Human hearing typically spans 20 Hz to 20,000 Hz (20 kHz), though the upper limit decreases with age. In practice, most adults cannot detect frequencies above 16-18 kHz.
- How do I convert RPM to Hz?
- Divide RPM by 60. A motor spinning at 3,600 RPM rotates at 60 Hz. This matters for matching motor speed to AC power frequency or for vibration analysis.
- What frequency does 5G use?
- 5G uses sub-6 GHz bands (600 MHz to 6 GHz) for broad coverage and mmWave bands (24-100 GHz) for high-density urban areas. The higher the frequency, the greater the bandwidth but the shorter the range.