Inverted-V Antenna Calculator

An inverted-V is a centre-fed dipole with the two legs sloping down from a single high support, so you only need one tall mast or tree. That makes it a favourite for backyards and portable operating.

The legs run a couple of percent longer than a flat dipole because the drooping shape lowers the resonant frequency. Only the apex needs to be high; keep the included angle between the legs at 90 degrees or wider. It feeds near 50 ohms through a 1:1 current balun and radiates in a nearly omnidirectional pattern.

Cut lengths by band

BandTotal wire length (both legs)Each leg from the apex
160m76.45 m / 250.8 ft38.22 m / 125.4 ft
80m38.73 m / 127.1 ft19.37 m / 63.5 ft
60m27.11 m / 89.0 ft13.56 m / 44.5 ft
40m20.46 m / 67.1 ft10.23 m / 33.6 ft
30m14.35 m / 47.1 ft7.17 m / 23.5 ft
20m10.25 m / 33.6 ft5.12 m / 16.8 ft
17m8.02 m / 26.3 ft4.01 m / 13.2 ft
15m6.84 m / 22.5 ft3.42 m / 11.2 ft
12m5.82 m / 19.1 ft2.91 m / 9.6 ft
10m5.10 m / 16.7 ft2.55 m / 8.4 ft
6m2.88 m / 9.4 ft1.44 m / 4.7 ft

Model this antenna interactively → for gain, takeoff angle and azimuth/elevation patterns.

Frequently asked questions

What is the difference between a dipole and an inverted-V?

An inverted-V is a dipole whose legs slope down from one central support. It needs only one high point, has a lower and more omnidirectional pattern, and its legs are cut slightly longer than a flat dipole.

How high should the apex of an inverted-V be?

As high as practical; about half a wavelength at the apex is ideal, and even a fifth of a wavelength works. Keep the leg ends at least head height off the ground.

What angle should the inverted-V legs be?

Keep the included angle between the two legs at 90 degrees or wider. Narrower angles lower the feed impedance and efficiency.

Does an inverted-V need a balun?

Yes, a 1:1 current balun at the feedpoint. The sloping legs pull the impedance close to 50 ohms, so no impedance transformer is needed.

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