The wave speed calculator uses v = fλ to find wave speed, frequency, or wavelength. Supports Hz, kHz, MHz for frequency and m/s, ft/s for speed. Works for sound, light, water waves, and any periodic wave.
Wave Speed Calculator (v = fλ)
How to Use the Wave Speed Calculator
This wave speed calculator solves v = fλ for any of three variables. Use speed presets for common media or enter custom values.
Frequency Units
Select Hz, kHz (×1000 Hz), MHz (×10⁶ Hz), or GHz (×10⁹ Hz) from the dropdown. The calculator converts automatically. For visible light (400-700 THz), enter in GHz × 1000 or use a conversion first.
Example: Musical Note A4
A4 = 440 Hz. Speed of sound in air = 343 m/s. Wavelength = 343 / 440 = 0.780 m (78 cm).
Common Wave Speeds
Sound in air (20°C): 343 m/s. Sound in water: 1,480 m/s. Sound in steel: 5,960 m/s. Light in vacuum: 299,792,458 m/s (3×10⁸). Light in glass: ~2×10⁸ m/s.
FAQ
What is the wave speed formula?
Wave speed v = f × λ, where f is frequency in Hz (cycles per second) and λ (lambda) is wavelength in meters. Rearranging: f = v/λ and λ = v/f. For sound in air at 20°C, v ≈ 343 m/s. For light in vacuum, v = 3 × 10⁸ m/s.
What is the speed of sound at different temperatures?
Sound speed in air increases with temperature: v ≈ 331.3 × √(T/273.15) m/s, where T is temperature in Kelvin. At 0°C: 331 m/s. At 20°C: 343 m/s. At 37°C (body temperature): 353 m/s. In water: ~1,480 m/s. In steel: ~5,960 m/s.
Is this calculator free?
Yes, completely free with no signup required. All calculations run in your browser.
Is my data private?
Yes. All calculations run locally. Nothing is transmitted.
What are common wave frequencies and wavelengths?
Human hearing: 20 Hz to 20,000 Hz (wavelengths 17 m to 1.7 cm in air). FM radio: 88-108 MHz (wavelengths 2.8-3.4 m). Visible light: 400-700 THz (wavelengths 700-400 nm). Microwave: ~2.4 GHz (wavelength ~12.5 cm). X-rays: 10¹⁷ Hz (wavelength ~0.1 nm).