Dipole Antenna Calculator
Free dipole antenna calculator: 468 ÷ f MHz gives half-wave length — a 40 m dipole cuts to 65 ft 5 in. Presets for 160 m–70 cm, inverted-V and loop too.
Dipole Antenna Calculator
Total Dipole Length
65′ 11″
Each Leg (234 ÷ f)
32′ 11.5″
In Meters
20.09 m
Formula
468 ÷ MHz ft
| Band | Freq | Dipole Total (468/f) | Each Leg |
|---|---|---|---|
| 80 m | 3.6 MHz | 130′ 0″ | 65′ 0″ |
| 40 m | 7.1 MHz | 65′ 11″ | 32′ 11.5″ |
| 20 m | 14.2 MHz | 32′ 11.5″ | 16′ 5.7″ |
| 15 m | 21.2 MHz | 22′ 0.9″ | 11′ 0.5″ |
| 10 m | 28.4 MHz | 16′ 5.7″ | 8′ 2.9″ |
| 6 m | 50.1 MHz | 9′ 4.1″ | 4′ 8″ |
| 2 m | 146 MHz | 3′ 2.5″ | 1′ 7.2″ |
ℹ️ 468 ÷ f is a starting point — height, wire gauge and insulation shift resonance 2-5%. Cut each leg a few inches long, then trim equally from both ends against an SWR meter or antenna analyzer.