Half Wave Dipole Calculator
Quick and Easy - Perfect for POTA use
Enter a frequency in either MHz or kHz.
Examples: 7.2 or 7200
Results will appear here.
Important Antenna Tuning Notes:
- Calculated lengths are approximate starting points only and should be used as an initial reference during antenna construction.
- Final dipole length will vary depending on wire diameter, insulation type, height above ground, nearby structures, trees, gutters, towers, and local installation environment.
- Insulated wire typically requires slightly shorter final lengths than bare wire.
- Most dipoles are intentionally cut slightly longer initially and then trimmed for final resonance and lowest SWR.
- Feedline type and feedline length may influence measured SWR and tuning characteristics, especially on multiband or non-resonant installations.
- Coaxial cable velocity factor, common mode current, balun use, choke design, and nearby conductive objects may affect antenna tuning and feedpoint impedance.
- Use of a current balun or choke balun at the feedpoint is commonly recommended to reduce feedline radiation and improve antenna symmetry.
- Actual resonant frequency may shift after the antenna is raised to final height.
- An antenna analyzer or SWR meter should be used for final tuning and verification.
- Weather, moisture, ice, and surrounding terrain may also affect final performance.
W5SWL Electronics – Amateur Radio Antenna Calculator