Antenna Calculator

I have recently added an antenna calculator to my website as displayed below.
Remember that these are approximate numbers. Always start a little longer than the displayed lengths, then with an SWR meter and/or antenna analyzer connected, trim the lengths until you have a good low SWR across most of the band, or at least towards the center of the band, or in the area you tend to use most. People that primarily use CW will want lower SWR at the lower end of the bands, versus voice users will want it closer to the center of the band.
After this, be sure to run your coax to the transceivers location and test it again with the SWR meter/antenna analyzer at the radio end of the coax to ensure the coax itself doesn't throw the SWR off by much, or the coax isn't compromised.

Calculate the frequency / length of antennas

This will work with any entry in any item of the form. For example, if you enter 144MHz, it should display 19.5 inch quarter wavelength. If you enter 108 (inches) for quarter wavelength, it should fill in the rest including the resonant frequency of 26MHz.

This will calculate the total length of a half wave dipole.

Half wave dipole length is useful for situations where you may need to feed it somewhere off center, to create an off center fed dipole (aka Windom).