Wave Frequency / Wavelength Calculator
Calculate wavelength, frequency, or wave speed using v = f × λ. Light, sound, and any wave phenomenon.
What is Wave Frequency / Wavelength Calculator?
The wave frequency calculator uses v = f × λ — the fundamental wave equation relating speed, frequency, and wavelength.
Formula
v = f × λ. Speed of sound in air: 343 m/s. Speed of light: 3 × 10⁸ m/s. Period T = 1/f.
Worked example
440 Hz (concert A) at sound speed 343 m/s: wavelength = 343/440 = 0.78 m. Visible light at 500 nm wavelength: f = 3×10⁸ / 500e-9 = 6 × 10¹⁴ Hz.
How to use this calculator
- Enter wave speed (343 for sound, 3e8 for light).
- Enter frequency or wavelength; leave the other blank.
Frequently asked questions
What's the speed of light?
Exactly 299,792,458 m/s in vacuum. Often rounded to 3 × 10⁸ m/s. Slower in materials (e.g., 200,000 km/s in water).
Speed of sound?
About 343 m/s in air at 20°C, 760 mph. Faster in water (~1500 m/s) and steel (~5000 m/s). Slower at lower temperatures.
Visible light wavelengths?
Red ~700 nm. Orange ~620 nm. Yellow ~580 nm. Green ~530 nm. Blue ~470 nm. Violet ~400 nm. Frequencies are in the 4-7 × 10¹⁴ Hz range.
Audible frequencies?
Humans hear roughly 20 Hz to 20 kHz. Below = infrasound (felt as vibration). Above = ultrasound (used in medical imaging, dog whistles).