Calculator inputs
Use the mode selector to solve for wavelength, frequency, or propagation speed. Results appear above this form after submission.
Example data table
These sample rows use common media and frequencies to illustrate how strongly wavelength changes with sound speed.
| Medium | Temperature (°C) | Speed (m/s) | Frequency (Hz) | Wavelength (m) |
|---|---|---|---|---|
| Air | 20 | 343.42 | 125 | 2.74736 |
| Air | 20 | 343.42 | 1,000 | 0.34342 |
| Fresh Water | 25 | 1,495.200 | 5 | 2.9904 |
| Steel | 20 | 5,960.000 | 1,000 | 5.96 |
| Helium | 20 | 1,007.000 | 2,000 | 0.5035 |
Formula used
λ = v / f
Here, λ is wavelength, v is sound speed, and f is frequency. Increasing sound speed increases wavelength, while increasing frequency decreases wavelength.
f = v / λ
v = f × λ
These forms help you solve for missing frequency or sound speed when the other two values are known.
T = 1 / f
k = 2π / λ
ω = 2πf
t = d / v
φ = 2πd / λ
The calculator also reports period, wave number, angular frequency, travel time, and phase shift across a selected path distance.
How to use this calculator
- Choose whether you want to solve for wavelength, frequency, or sound speed.
- Select a medium. Air, water, and seawater use temperature-sensitive speed estimates.
- Enter custom speed only when using a custom medium or when comparing measured values.
- Fill in the known frequency or wavelength and choose matching input units.
- Add a path distance to estimate travel time, phase shift, and total cycles.
- Press the calculate button. The result block will appear above the form, followed by the wave graph and export tools.
Frequently asked questions
1. What is acoustic wavelength?
Acoustic wavelength is the physical length of one complete sound-wave cycle. It tells you how far a wave travels before its pattern repeats in space.
2. How do frequency and wavelength relate?
They are inversely related when wave speed is fixed. Higher frequency means shorter wavelength, while lower frequency means longer wavelength.
3. Why does the medium matter?
Sound speed changes by medium. Because wavelength equals speed divided by frequency, the same frequency produces different wavelengths in air, water, or steel.
4. Does temperature affect wavelength?
Yes. In gases and liquids, temperature often changes sound speed. When speed changes and frequency stays constant, wavelength changes too.
5. What is wave number?
Wave number measures spatial repetition in radians per meter. It equals 2π divided by wavelength, so shorter wavelengths produce larger wave numbers.
6. What does phase shift over distance mean?
Phase shift shows how much a wave advances after traveling a chosen distance. It is useful when comparing sensors, microphones, or transmission paths.
7. Can I use this for ultrasound?
Yes. Enter the ultrasonic frequency and the correct propagation speed for the material. The formula remains the same at higher frequencies.
8. When should I use custom speed?
Use custom speed when you have measured data, a special material, or a better reference value than the built-in estimates.