Wave Speed Calculator
Solve v = f·λ for any one of the three variables. Leave one field blank.
Leave exactly one field blank.
Formula
v = f · λ (speed = frequency × wavelength)
Period T = 1 / f
Period T = 1 / f
Physics behind v = fλ
Every periodic wave — sound, light, water ripples, seismic waves — satisfies the relation v = f·λ. Imagine crests going past a fixed point: if f crests pass per second and the distance between crests is λ, then the wave has travelled f·λ metres in that second. Crucially, in a given medium the wave speed is fixed, so increasing the frequency must decrease the wavelength, and vice versa. That's why a high-pitched violin note has a shorter wavelength than a low bass note in the same air.
Worked example
f = 50 Hz, λ = 2 m
v = f·λ = 50 × 2 = 100 m/s
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FAQs
What is the wave equation v = fλ?
Wave speed equals frequency times wavelength.
What is the speed of sound in air?
About 343 m/s at 20 °C.
What is the speed of light?
Exactly 299,792,458 m/s in vacuum.