Antenna length calculator
Type a frequency to see the wavelength and the common antenna lengths for it.
| Antenna | Length |
|---|---|
| Full wavelengthDistance one wave travels. | 25.5 in (64.8 cm) |
| Half waveCommon for base and dipole antennas. | 12.8 in (32.4 cm) |
| Quarter wave in free spaceTheory number before trimming. | 6.4 in (16.2 cm) |
| Quarter wave to cut (about 95%)A practical starting length for a simple whip. Trim to the lowest SWR. | 6.1 in (15.4 cm) |
| 5/8 wavePopular for mobile antennas with a matching coil. | 15.9 in (40.5 cm) |
Lengths are estimates. Real antennas shift with their thickness, mounting and surroundings, so always check SWR and trim a little at a time.
