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Frequency Converter

Convert frequency values between Hertz, kilohertz, megahertz, gigahertz, RPM (revolutions per minute), and radians per second. Covers electronics, radio communications, mechanical engineering, acoustics, and signal processing applications.

Reviewed by Chase FloiedUpdated

This free online frequency converter provides instant results with no signup required. All calculations run directly in your browser — your data is never sent to a server. Enter your values below and see results update in real time as you type. Perfect for everyday calculations, homework, or professional use.

The frequency to convert

Source frequency unit

Target frequency unit

How to Use This Calculator

1

Enter your input values

Fill in all required input fields for the Frequency Converter. Most fields include unit selectors so you can work in your preferred unit system — metric or imperial, whichever matches your problem.

2

Review your inputs

Double-check that all values are correct and that you have selected the right units for each field. Incorrect units are the most common source of calculation errors and can produce results that are off by factors of 2, 10, or more.

3

Read the results

The Frequency Converter instantly computes the output and displays results with units clearly labeled. All calculations happen in your browser — no loading time and no data sent to a server.

4

Explore parameter sensitivity

Try adjusting individual input values to see how the output changes. This is a quick and effective way to develop intuition about how different parameters influence the result and to identify which inputs have the largest effect.

Formula Reference

Frequency Converter Formula

See calculator inputs for the governing equation

Variables: All variables and their units are labeled in the calculator interface above. Input fields accept values in multiple unit systems — select your preferred unit from the dropdown next to each field.

When to Use This Calculator

  • Use the Frequency Converter when you need accurate results quickly without the risk of manual computation errors or unit conversion mistakes.
  • Use it to verify calculations made by hand or in spreadsheets — an independent check can catch errors before they lead to costly decisions.
  • Use it to explore how changing input parameters affects the output — a quick way to develop intuition and identify the most influential variables.
  • Use it when collaborating with others to ensure everyone is working from the same numbers and applying the same assumptions.

About This Calculator

The Frequency Converter is a free, browser-based calculation tool for engineers, students, and technical professionals. Convert frequency values between Hertz, kilohertz, megahertz, gigahertz, RPM (revolutions per minute), and radians per second. Covers electronics, radio communications, mechanical engineering, acoustics, and signal processing applications. It implements standard formulas and supports both metric (SI) and imperial unit systems with automatic unit conversion. All calculations are performed instantly in your browser with no data sent to a server. Use this calculator as a quick reference and sanity-check tool during design, analysis, and learning. Always verify results against primary engineering references and applicable standards for any safety-critical application.

About Frequency Converter

The Frequency Converter enables precise conversions between the most common frequency and rotational speed units. Hertz and its SI multiples (kHz, MHz, GHz) are the standard for electronics, radio, computing, and acoustics. RPM measures rotational speed of motors, engines, and turbines. Radians per second is the angular frequency used in physics and control systems engineering. This tool bridges the gap between these different representations of periodic phenomena, making it easy to work across disciplines from signal processing to mechanical engineering.

The Math Behind It

Frequency measures how often a periodic event occurs per unit time. The SI unit is the Hertz (Hz), equal to one cycle per second, named after Heinrich Hertz who first demonstrated electromagnetic waves. The metric prefixes scale Hertz for different applications: kilohertz (kHz, thousands of Hz) for audio frequencies and AM radio, megahertz (MHz, millions of Hz) for FM radio and older processors, and gigahertz (GHz, billions of Hz) for modern computer processors, Wi-Fi, and microwave communications. A typical smartphone processor runs at 2-3 GHz, executing billions of clock cycles per second. RPM (revolutions per minute) measures rotational speed. Car engines idle at about 600-900 RPM, hard drives spin at 5400-7200 RPM, and jet engine turbines reach 10,000-40,000 RPM. To convert RPM to Hertz, divide by 60 (since there are 60 seconds per minute). One RPM equals 1/60 Hz. Radians per second (rad/s) is the angular frequency, often denoted omega. It relates to Hertz by omega = 2*pi*f, where f is frequency in Hz. Angular frequency is the natural unit for physics equations involving rotation and oscillation: the simple harmonic oscillator equation uses omega, not Hz. Control systems engineers work primarily in rad/s because transfer functions are expressed in the Laplace domain using omega. Frequency and period are reciprocals: T = 1/f. A 1 kHz signal has a period of 1 millisecond. This relationship is fundamental in timing applications, digital communications, and waveform analysis. The audible frequency range for humans is approximately 20 Hz to 20 kHz, though this decreases with age. Middle C on a piano is approximately 261.63 Hz. The electromagnetic spectrum extends from extremely low frequencies (3-30 Hz) through radio, microwave, infrared, visible light (430-770 THz), ultraviolet, X-rays, to gamma rays (above 10^19 Hz).

Formula Reference

Frequency Conversion via Hertz

result = value * toHz[from] * fromHz[to]

Variables: value = input frequency, toHz = factor to Hz, fromHz = factor from Hz

Worked Examples

Example 1: Radio: MHz to Hz

Convert an FM radio station at 101.5 MHz to Hertz.

Step 1:Apply conversion: 101.5 * 1,000,000 = 101,500,000 Hz

101.5 MHz equals 101.5 million Hertz (101,500,000 Hz).

Example 2: Motor: RPM to rad/s

Convert a 3600 RPM motor speed to radians per second.

Step 1:Convert RPM to Hz: 3600 / 60 = 60 Hz
Step 2:Convert Hz to rad/s: 60 * 2 * pi = 376.99 rad/s

3600 RPM equals approximately 377 rad/s.

Example 3: Processor: GHz to MHz

Convert a 2.4 GHz processor clock to MHz.

Step 1:Apply conversion: 2.4 * 1000 = 2400 MHz

2.4 GHz equals 2400 MHz.

Common Mistakes & Tips

  • !Forgetting the 2*pi factor when converting between Hz and rad/s. One Hz equals 2*pi rad/s (approximately 6.283), not 1 rad/s.
  • !Confusing frequency (Hz) with angular frequency (rad/s). While both describe periodic phenomena, they differ by a factor of 2*pi and are not interchangeable in formulas.
  • !Assuming RPM and Hz are the same. RPM measures revolutions per minute while Hz measures cycles per second. Divide RPM by 60 to get Hz.

Related Concepts

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Frequently Asked Questions

What is the relationship between frequency and wavelength?

Wavelength = speed / frequency. For electromagnetic waves in vacuum, wavelength (m) = 299,792,458 / frequency (Hz). For sound in air at 20 degrees C, wavelength (m) = 343 / frequency (Hz). Higher frequency means shorter wavelength.

Why do computer processors use GHz?

Modern processors execute instructions on clock cycles. A 3 GHz processor completes 3 billion cycles per second. Higher clock speeds generally mean faster execution, though actual performance also depends on instructions per cycle, architecture, and parallelism.

What frequency is middle C on a piano?

Middle C (C4) is approximately 261.63 Hz in the standard equal temperament tuning system with A4 = 440 Hz. Each octave doubles the frequency, so C5 is 523.25 Hz and C3 is 130.81 Hz.