Enter your frequency, choose your measurement units, dipole type, and wire diameter, and the Dipole Antenna Calculator gives you the total dipole length, each element length, wavelength, and input impedance — everything you need to cut your antenna to the right size on the first try.
Total Dipole Length
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Each Element Length
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Wavelength
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Input Impedance
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A half-wave dipole should be approximately 95% of the theoretical half wavelength due to the shortening factor. The calculator accounts for wire thickness and applies the appropriate correction factor for accurate results.
Larger wire diameter increases bandwidth and requires a greater shortening factor. Typical wire sizes range from 16 AWG to 12 AWG, with thicker wire providing wider bandwidth but requiring more correction to achieve resonance.
A theoretical half-wave dipole has an impedance of 73.129 Ω. Real-world dipoles typically show 50-75 Ω depending on height above ground, nearby objects, and construction details.
Yes, a 1:1 balun is recommended to match the balanced dipole to unbalanced coax cable. This prevents stray RF currents on the feedline and reduces interference in your station.
Calculations provide a good starting point, typically within 1-2% of optimal length. Fine-tuning with an SWR meter is recommended for best performance, as environmental factors affect the final dimensions.
Folded dipoles have 4 times higher impedance (around 300 Ω) and wider bandwidth than straight dipoles. They use the same overall length but have a folded construction that creates different electrical characteristics.
Yes, the calculator works for any frequency from HF through microwave. At VHF/UHF frequencies, dipoles become very short, making precise construction more critical for good performance.
Mount dipoles at least one wavelength high for best performance. Minimum height is typically one-quarter wavelength above ground or obstacles. Higher mounting generally improves radiation pattern and reduces ground losses.