Calculate rotational surface speed from frequency and diameter, or wave speed from frequency and wavelength in m/s, km/h, and ft/s.
- All Unit Converters
- Waves, Optics, and Quantum Unit Converters
- Hz to Rpm Calculator
- Hz To Joules Calculator
Wave Speed Formula (v = f × λ)
In the Wave (f·λ) tab, the following formula is used to calculate the speed of a wave.
S = F \times \lambda
Variables:
- S is the speed of the wave (meters per second)
- F is the frequency of the wave (hertz, Hz)
- λ is the wavelength (meters, m)
To calculate the speed of a wave, multiply the frequency (in hertz) by the wavelength (in meters). For rotational surface (rim) speed of a wheel/roller, the relationship is v = π × D × f (with f in Hz = revolutions per second and D as diameter), which is what the rotational table below uses.
| Frequency (Hz) | Speed (m/s) | Speed (ft/s) |
|---|---|---|
| 0.25 | 0.785 | 2.577 |
| 0.50 | 1.571 | 5.154 |
| 1 | 3.142 | 10.307 |
| 2 | 6.283 | 20.614 |
| 3 | 9.425 | 30.921 |
| 4 | 12.566 | 41.228 |
| 5 | 15.708 | 51.535 |
| 7.5 | 23.562 | 77.303 |
| 10 | 31.416 | 103.071 |
| 12 | 37.699 | 123.685 |
| 15 | 47.124 | 154.606 |
| 20 | 62.832 | 206.141 |
| 25 | 78.540 | 257.677 |
| 30 | 94.248 | 309.212 |
| 40 | 125.664 | 412.283 |
| 50 | 157.080 | 515.353 |
| 60 | 188.496 | 618.424 |
| 75 | 235.619 | 773.030 |
| 100 | 314.159 | 1030.706 |
| 120 | 376.991 | 1236.848 |
| * Rounded to 3 decimals. Assumes diameter D = 1.00 m. For rotational motion: v = π × D × f, where f is rotational frequency (1 Hz = 1 revolution per second). 1 m/s = 3.28084 ft/s. | ||
What is Wave Speed?
Wave speed is the distance a wave travels per unit of time. It is a fundamental property of waves that depends on the medium through which the wave is traveling. In a vacuum, all electromagnetic waves (including light) travel at a constant speed, which is approximately 299,792,458 meters per second. In other media, the speed depends on the medium, and in dispersive media it can also vary with frequency.
How to Calculate Wave Speed?
The following steps outline how to calculate the speed of a wave.
- First, determine the frequency of the wave (F) in hertz (Hz).
- Next, determine the wavelength (λ) in meters (m).
- Use the formula from above: S = F × λ.
- Finally, calculate the speed of the wave (S) in meters per second.
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
frequency of the wave (F) = 500 Hz
wavelength (λ) = 2 meters
speed of the wave (S) = F × λ = 500 × 2 = 1000 m/s
