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Physics formula

How to calculate wave speed

Wave speed describes how fast a wave pattern travels through a medium.

See the formulaOpen calculator
Direct answer
Formula
v = f * lambda

Use the table below to match each symbol with the right input. Keep units consistent before you start.

Wave speed formula
Start here when you only need the equation and variable names.
Formula
v = f * lambda

Wave speed describes how fast a wave pattern travels through a medium.

Variable meanings
Check each symbol, meaning, and unit before you calculate.
SymbolNameDescriptionUnit
vWave speedSpeed of the wave.m/s
fFrequencyCycles per second.Hz
lambdaWavelengthDistance between matching points on the wave.m
When to use this formula
Check that your situation matches the formula before you trust the result.
  • Works for sound, water, light in a medium, and other wave problems with known frequency and wavelength.
Step-by-step method
Follow these steps when you are solving it by hand.
  1. 1Convert frequency to hertz.
  2. 2Convert wavelength to meters.
  3. 3Multiply frequency by wavelength.
  4. 4Report speed in meters per second.
Examples
These sample numbers show the order of operations and units.
Long wave
f
50 Hz
lambda
2 m
  1. 1.v = 50 * 2
  2. 2.v = 100 m/s
Result
The wave speed is 100 m/s.
Sound-like wave
f
440 Hz
lambda
0.78 m
  1. 1.v = 440 * 0.78
  2. 2.v = 343.2 m/s
Result
The wave speed is 343.2 m/s.
Mistakes to avoid
Small input or unit errors can change the answer a lot.
  • Mixing metric and imperial units before solving the wave speed formula.
  • Forgetting squared units such as m^2, m/s^2, or velocity squared.
  • Dropping negative signs when direction matters.
  • Rounding measured values too early in the calculation.
Open the Wave Calculator
Open the calculator for the answer without rewriting the formula.

Enter your values in the related calculator, then compare the output with the hand method above.

Open Wave Calculator
FAQs
Short answers for common formula questions.
Can I calculate Wave speed by hand?

Yes. Write the units next to each value, convert rates or measurements first, and round only the final answer.

Why does my Wave speed result differ from another calculator?

Most differences come from rounding, unit conversions, rate timing, or a slightly different version of the formula.

When is the Wave Calculator better than hand math?

Open the Wave Calculator to check several scenarios or skip the hand arithmetic.