Frequency Converter

About the Frequency Converter

A frequency converter translates between hertz (Hz), kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz), and related units including radians per second (rad/s) and revolutions per minute (RPM). Frequency — the number of cycles or oscillations per second — is a fundamental quantity in physics, engineering, and everyday technology. Audio engineers work with frequencies from 20 Hz to 20 kHz (the human hearing range). Radio engineers work with megahertz and gigahertz for broadcast and wireless communications. Computer hardware designers work with gigahertz CPU clock speeds. Mechanical engineers work with RPM for rotating machinery. Physicists work with terahertz for optical and quantum systems. Our calculator converts between all frequency units, shows the equivalent period (time per cycle), and for electromagnetic radiation, calculates the corresponding wavelength using the speed of light.

How It Works

Frequency prefix conversions: 1 kHz = 1,000 Hz; 1 MHz = 1,000,000 Hz; 1 GHz = 1,000,000,000 Hz; 1 THz = 10^12 Hz. Period (T) = 1/f. Radians per second: omega = 2 x pi x f. RPM to Hz: f = RPM/60. Electromagnetic wavelength: lambda = c/f, where c = 299,792,458 m/s. Examples: 2.4 GHz WiFi wavelength = 3x10^8 / 2.4x10^9 = 0.125 m = 12.5 cm. Middle C (261.6 Hz): period = 1/261.6 = 3.82 ms. A 3,000 RPM motor: f = 3,000/60 = 50 Hz. A 5 GHz CPU: clock period = 1/(5x10^9) = 0.2 nanoseconds per clock cycle.

Tips & Best Practices

• ✓Human hearing range: 20 Hz to 20,000 Hz (20 kHz). Ultrasound is above 20 kHz; infrasound is below 20 Hz.
• ✓Modern CPUs run at 3-5 GHz — 3 to 5 billion clock cycles per second, each cycle capable of executing one or more instructions.
• ✓WiFi channels: 2.4 GHz band has 14 channels (1, 6, 11 are non-overlapping in the US); 5 GHz has more channels with less interference but shorter range.
• ✓Musical note A4 = 440 Hz — the international standard tuning reference for orchestral instruments.
• ✓AC power frequency: 60 Hz in North America, Japan; 50 Hz in Europe, Asia, Africa, Australia.
• ✓Visible light frequency: approximately 400-790 THz (wavelengths 380-750 nm). Red light is approximately 430 THz; violet is approximately 750 THz.
• ✓5G mmWave: operates at 24-100 GHz with very short wavelengths (1-12 mm), enabling massive data throughput but limited range and poor building penetration.
• ✓Resonant frequency: every mechanical system has a natural resonant frequency. The Tacoma Narrows Bridge collapsed in 1940 because wind created oscillations near the bridge's resonant frequency — a dramatic engineering lesson.

Who Uses This Calculator

Audio engineers designing speaker systems and equalisation filters. RF engineers planning wireless communication systems and antenna design. Computer hardware engineers working with clock frequencies and timing. Physicists calculating electromagnetic wavelengths from frequency. Mechanical engineers analysing vibration and rotating machinery. Students in physics and engineering courses converting between SI frequency units.