Wavelength

How to use this calculator

Wavelength is the physical length of one cycle of a wave: λ = v / f, where v is the propagation velocity. In free space v = c (≈ 3×10⁸ m/s), but in a cable, dielectric, or PCB trace the wave slows by the velocity factor k, so v = c·k. Enter the frequency, choose a preset medium (or type a custom k), and λ is shown in km, m, cm or mm — plus λ/2, a common antenna length.

What it means in a real circuit

Wavelength is the bridge between electrical frequency and physical size. It governs antenna dimensions (a half‑wave dipole is λ/2 long), transmission‑line behaviour (a line becomes "electrically long" above ~λ/20), and the spacing of RF components. When designing for RF, always use the guided wavelength in the actual medium, not the free‑space value, or your physical layout will be wrong.