Frequency Converter - Hz, kHz, MHz, GHz, THz, RPM, rad/s Online Tool

Hertz (Hz) - The SI Unit of Frequency

The Hertz (Hz) is the SI unit of frequency, defined as one cycle per second. It measures how many times a periodic event repeats each second. The unit was named after the German physicist Heinrich Hertz, who conclusively proved the existence of electromagnetic waves in the late 19th century. One Hertz simply means "one cycle per second." For example, a standard tuning fork for the musical note A above middle C vibrates at 440 Hz - 440 cycles per second. The human ear can typically hear frequencies between 20 Hz (very low bass) and 20,000 Hz (very high treble), though this range narrows with age. Frequency (f) is inversely related to the time period (T) of a wave by the formula: f = 1/T. So if a wave takes 0.01 seconds to complete one cycle (T = 0.01 s), its frequency is 100 Hz. This relationship is fundamental to understanding waveforms across all domains of physics and engineering.

Kilohertz (kHz) - Audio and Radio Frequencies

One kilohertz (kHz) equals 1,000 Hertz. This unit is commonly used for audio frequencies and lower-range radio signals. The AM radio band, for example, spans from 530 kHz to 1,700 kHz. In audio, CD-quality sound is sampled at 44.1 kHz (44,100 samples per second), which is based on the Nyquist theorem to accurately reproduce frequencies up to 22.05 kHz. Ultrasound imaging typically uses frequencies between 2 and 18 MHz, but diagnostic applications often start in the lower MHz range. To convert Hz to kHz, simply divide by 1,000. For example, 5,000 Hz = 5 kHz. Conversely, to convert kHz to Hz, multiply by 1,000. Our tool makes these conversions instant and accurate.

Megahertz (MHz) - Radio, Television, and Processor Speeds

One megahertz (MHz) equals 1,000,000 Hertz. This unit is widely used for VHF and UHF radio bands, television broadcasts, and older computer processor speeds. FM radio stations broadcast in the 88-108 MHz range. Early personal computers had CPU speeds measured in MHz - the Intel 80486 DX2, for example, ran at 66 MHz. Modern processors have since moved to the GHz range, but MHz is still used for many communication applications. To convert MHz to Hz, multiply by 1,000,000. To convert MHz to kHz, multiply by 1,000. To convert MHz to GHz, divide by 1,000.

Gigahertz (GHz) - Modern Computing and Wireless Communications

One gigahertz (GHz) equals 1,000,000,000 Hertz (10⁹ Hz). This is the standard unit for modern computer processor clock speeds (typically 2.0 to 5.0 GHz as of 2026), as well as microwave frequencies. Microwave ovens operate at 2.45 GHz, which is specifically chosen because water molecules absorb energy at that frequency, heating food efficiently. Wi-Fi networks use the 2.4 GHz and 5 GHz bands, and newer standards like Wi-Fi 6E use the 6 GHz band. 5G cellular networks utilize frequencies up to 39 GHz in the "millimeter wave" range. To convert GHz to Hz, multiply by 1,000,000,000. To convert GHz to MHz, multiply by 1,000. To convert GHz to kHz, multiply by 1,000,000.

Terahertz (THz) - Cutting-Edge Science and Imaging

One terahertz (THz) equals 1,000,000,000,000 Hertz (10¹² Hz). The terahertz range lies between microwaves and infrared light. Terahertz radiation has unique properties: it can penetrate many materials (like clothing, paper, and plastic) without the ionizing risks of X-rays, making it valuable for security imaging and non-destructive testing. Terahertz spectroscopy is also used in pharmaceutical analysis, astronomy (to study cold interstellar dust), and communications research. While not yet common in consumer electronics, THz technology is an active area of research.

Revolutions per Minute (RPM) - Mechanical Rotational Speed

RPM (revolutions per minute) measures rotational speed: how many complete rotations an object makes in one minute. It is commonly used for engines, motors, fans, hard drives, and any rotating machinery. To convert RPM to Hz, divide by 60 because there are 60 seconds in a minute. For example, a motor spinning at 3,600 RPM produces a frequency of 60 Hz - exactly the standard AC power frequency in the United States. Conversely, to convert Hz to RPM, multiply by 60. Our tool handles these conversions with precision, making it valuable for mechanical engineers, automotive technicians, and hobbyists.

Radians per Second (rad/s) - Angular Frequency in Physics

Radians per second (rad/s) is the SI unit of angular velocity. One complete revolution (360°) equals 2π radians. Therefore, a rotation of 1 revolution per second corresponds to 2π rad/s. In AC circuit analysis and wave physics, angular frequency (ω) is often used instead of ordinary frequency (f). The relationship is: ω = 2πf. To convert rad/s to Hz, divide by 2π (approximately 6.28318). To convert Hz to rad/s, multiply by 2π. Our tool includes this conversion automatically, saving you from manual calculations.

Degrees per Second (°/s) - Navigation and Robotics

Degrees per second (°/s) measures angular speed in degrees of arc per second. It is commonly used in navigation, robotics, and gyroscopic sensors. A full rotation is 360 degrees, so 1 revolution per second equals 360°/s. To convert °/s to Hz, divide by 360. This unit is particularly useful for describing slow rotational motions where RPM values would be fractional and less intuitive.

How accurate is this frequency converter?

Our frequency converter uses exact mathematical conversion factors (e.g., 1 kHz = 1,000 Hz exactly, 2π for rad/s to Hz). Results are displayed to 6 decimal places, which is more than sufficient for virtually all engineering, physics, and educational purposes. The tool uses JavaScript's 64-bit floating-point arithmetic, ensuring high precision.

What is the difference between Hz and RPM?

Hertz (Hz) measures cycles per second, while RPM measures revolutions per minute. There are 60 seconds in a minute, so 1 RPM = 1/60 Hz ≈ 0.01667 Hz. Conversely, 1 Hz = 60 RPM. Our tool handles this conversion automatically.

How do I convert rad/s to Hz?

To convert radians per second (rad/s) to Hertz (Hz), divide the rad/s value by 2π (approximately 6.283185307). The exact formula is: f = ω / 2π where ω is angular frequency in rad/s. For example, 6.28318 rad/s equals 1 Hz.

Can I convert between frequency and period using this tool?

This tool directly converts between frequency units. The relationship between frequency (f) and period (T) is T = 1/f. So if you have a frequency in Hz, the period in seconds is 1 divided by that frequency. Our tool focuses on frequency unit conversions, but you can easily derive the period using the reciprocal relationship.

Does this frequency converter work offline?

Yes, once the page is loaded, all conversion logic runs locally in your browser using JavaScript. No internet connection is required for the tool to function, making it reliable for use anywhere.

Is my data secure when using this online frequency converter?

Absolutely. All calculations are performed entirely on your device. No data is transmitted to any server. Your input values are saved locally in your browser's localStorage only for your convenience (30-day retention) and are never shared or collected.

What is the difference between a frequency converter tool and a VFD?

This is an important distinction. Our tool is a software frequency unit converter that changes how a frequency value is expressed (e.g., from Hz to kHz). A Variable Frequency Drive (VFD)is a physical electronic device used to control the speed of an AC electric motor by varying the output frequency and voltage. They serve completely different purposes.

Why do some countries use 50 Hz and others 60 Hz for mains power?

This is a historical engineering difference. The United States adopted 60 Hz (influenced by Nikola Tesla and Westinghouse), while Europe standardized on 50 Hz. Most of the world uses either 50 Hz or 60 Hz depending on the region. Japan uniquely uses both: 50 Hz in Eastern Japan and 60 Hz in Western Japan. Our converter can help you understand the frequency differences if you're traveling with electronic devices.