Wave Equations

The Wave Equation

v = f × λ. Wave speed (m/s) = Frequency (Hz) × Wavelength (m). Rearranged: f = v/λ and λ = v/f. For light in a vacuum: v = c = 299,792,458 m/s ≈ 3 × 10⁸ m/s.

The EM Spectrum

Radio waves: λ > 1mm (f < 300 GHz). Microwaves: 1mm–1m. Infrared: 700nm–1mm. Visible light: 400–700nm. UV: 10–400nm. X-rays: 0.01–10nm. Gamma rays: λ < 0.01nm. Higher frequency = more energy.

Sound Frequencies

Human hearing: 20Hz–20,000Hz. Middle C: 261.6Hz. Dog hearing: up to 65,000Hz. Ultrasound (medical): 1–20 MHz. A 440Hz note (concert A) has a wavelength of 0.78m in air at room temperature.

Wavelength & Frequency Calculator

Results update automatically as you type

Enter values above to calculate