Frequency Calculator
Frequency counts how many complete wave cycles pass a point each second. It is the bridge between the speed of a wave, its wavelength, and the time one cycle takes, and it is quoted in hertz.
Frequency
170
- Period
- 0.0059
- Period in milliseconds
- 5.8824
- Angular frequency
- 1,068.1415
- Wavelength in use
- 2
Values update as you type. This calculator covers the single scenario its formula assumes — see Common Mistakes for what it leaves out.
The formula this calculator uses
f = v / lambda, or f = 1 / T
- f
- Frequency, in hertz (cycles per second)
- v
- Wave speed, in metres per second
- lambda
- Wavelength, in metres
- T
- Period, the time for one cycle, in seconds
How to check the result by hand
- 1
Write down what you know
Note the wave speed and the wavelength, or the period. The 340 metres per second example uses a 2 metre wavelength, and both numbers are already in SI units so no conversion is needed.
- 2
Divide speed by wavelength
340 divided by 2 is 170. Because the metres cancel, the answer carries the unit per second, which is the hertz.
- 3
Check with the period
The period is the reciprocal of the frequency, so 1 divided by 170 is 0.005882 seconds. That is about 5.9 milliseconds per cycle, which is consistent with a low audible tone.
- 4
Convert to angular frequency if needed
Multiply by two pi to get radians per second. Two times 3.14159 times 170 is about 1068 radians per second, the form used in wave equations.
For worked examples, common mistakes and the limits of this formula, read the full How To Calculate Frequency page.