Frequency Converter

How It Works

Frequency measures how many cycles or events occur per unit of time. This converter uses Hertz (Hz) as its base unit — 1 Hz means one cycle per second. All other units are stored as their Hz equivalent.

The Hertz (Hz) was named after Heinrich Hertz, who first conclusively demonstrated the existence of electromagnetic waves in 1887. The metric prefixes apply cleanly: 1 kHz = 1,000 Hz, 1 MHz = 10⁶ Hz, 1 GHz = 10⁹ Hz, 1 THz = 10¹² Hz. These prefixes span an enormous practical range — from audible sound (20 Hz–20 kHz) to radio waves (kHz–GHz) to visible light (400–790 THz).

Audio frequency range:
Humans hear from approximately 20 Hz (deep bass) to 20,000 Hz (20 kHz, high treble). Musical note A4 (concert A) = 440 Hz. Bats echolocate at 20–100 kHz; ultrasound medical imaging uses 2–18 MHz.

Radio frequency spectrum:
AM radio: 535–1,705 kHz. FM radio: 87.5–108 MHz. WiFi 2.4 GHz and 5 GHz bands. 5G mobile operates up to 52.6 GHz. Satellite communications use Ku band (~12–18 GHz).

Processor speed:
Modern CPUs run at 3–5 GHz (3–5 billion cycles per second). Each clock cycle takes about 0.2–0.33 nanoseconds.

Revolutions per minute (RPM) is a rotational frequency unit used for engines, motors, hard drives, and fans. 1 RPM = 1/60 Hz = 0.016667 Hz. A car engine idling at 800 RPM = 13.33 Hz. A hard drive spinning at 7,200 RPM = 120 Hz.

Radians per second (rad/s) is the SI unit for angular frequency (ω), related to ordinary frequency (f) by ω = 2πf. 1 Hz corresponds to 2π rad/s ≈ 6.2832 rad/s.

Worked example — WiFi channel:
2.4 GHz WiFi = 2,400,000,000 Hz = 2,400 MHz = 2.4 GHz.

Worked example — Engine speed:
6,000 RPM = 6,000 ÷ 60 = 100 Hz. In rad/s: 100 × 2π = 628.32 rad/s.

Worked example — Visible light:
Green light at 550 nm has frequency: f = c/λ = 3×10⁸ ÷ 550×10⁻⁹ = 545 THz.