Dragon Amateur Radio Club
Antenna Length Calculator
Calculate practical antenna lengths for common HF bands. Choose a wave fraction (¼, ½, 1λ), wire type, and formula. Always trim and tune in situ.
Pick a band to fill in a sensible centre frequency, or just type your own below.
Half-wave is used for centre-fed dipoles. Quarter-wave is handy for verticals/radials.
These formulas are commonly given for a half-wave reference; the calculator scales for ¼ and 1λ.
Used for choke recommendation wording.
A centre-fed dipole is balanced; coax is not.
Affects the balun/choke recommendation shown below.
Shown in the printable results for your build notes.
Tip: For dipoles, a 1:1 current balun/choke at the feedpoint is usually beneficial with coax.
Always start a little long, then trim to resonance.
Results
Enter a frequency to see lengths.
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