IconVault's Frequency Calculator converts between Hz, kHz, MHz and GHz, and derives the period, the wavelength in air, and the radio wavelength from any value. The musical tab maps any MIDI note to its frequency, finds the nearest note to a measured frequency (with cents offset), and lists note lengths in milliseconds at any BPM.

Useful for audio work, radio planning, and music production: delay times, tuning checks, and quick unit math in one place. Free and runs fully in your browser.