Frequency, Wavelength, Period and Speed



This page allows you to input two out of the four values for a simple A.C., RF or Audio problem, and calculate the remaining values, regardless of which two values are provided. Common uses might include radio antenna design, EMI filter design, etc.
Click on any of the links at the top of the page to reveal (or hide) more information about this calculator.


If you are reading this paragraph, then you probably don't have JavaScript installed/enabled on your computer.
At this point in time the calculators on this site are entirely dependent on JavaScript. Given enough time and money it is hoped to develop a version in the future which will be able to operate independently. Since JavaScript runs on your own computer, rather than on this server, it has been possible to set up this site much more quickly than if a server-side language was used, and it is possible to serve far more pages with the available bandwidth.
If you think that you can assist with this project in any way, then please visit the Support section and leave a message.


Frequency f
The number of times a full oscillation occurs within one second, measured in Hertz.
Time t
The period required for one complete oscillation, (ie: one complete wave), measured in Seconds.
Inversely proportional to the Frequency.
Wavelength λ (Greek lowercase letter lambda)
The distance between each positive peak of the waveform, or any other part of the wave, measured in metres.
In antenna design, there is often a requirement to use less than a full wavelength, and so additional fields are provided for ¼, ½, ¾ Wavelengths.
Speed / Velocity V
The speed of the transmission medium, measured in metres per second.
Buttons are provided below the entry field to allow you to specify certain common values. Note that for transmission antenna, a 'correction factor' may be needed depending on the kind of wire used.


Diagram of the "Magic Triangle" formulae: velocity = frequency times wavelength


  1. Fill in at least two boxes with the values that you know
  2. Make sure that only one of the four 'Wavelength' boxes has a value
  3. Make sure that only the 'Frequency' or the 'Time' box has a value
  4. Change the units for all 'input' fields, if required
  5. Change the units for any output fields to match the dimensions that you want to use.
  6. Click the 'CalcResult' button below the input fields
  7. The value of the blank fields will be calculated
  8. A 'Results Area' will be displayed below.
  9. All known values will be shown. (Values for which insufficient information was given will also be identified.)
  10. To do further calculations simply change any values in the input fields and click the 'CalcResult' button again. (Press the 'Clear Form' button if you want to empty all of the input fields.)
  11. Press the 'Clear Results' button if you wish to discard the first results, otherwise further calculations will be added into the same area.
  12. Click the 'CalcResult' button again
  13. Click the 'Print Results' button to display all current results in a new, printable window.
Time Values
Length Values
Transmission Speed


© Copyright Mike Brockington 2004 - 2021   All Rights Reserved