Dipole Antenna Calculator

Instructions

This calculator determines the approximate length of a half-wavelength dipole antenna. A dipole antenna is a fundamental and widely used antenna design.

Input: Enter the desired operating frequency in Megahertz (MHz). For example, for the 20-meter amateur radio band, you would enter 14 (MHz).

Calculation: Click the "Calculate" button. The calculator will determine the required length of each dipole leg (and the total length) based on the chosen units (imperial or metric).

Units: Use the buttons to toggle between imperial (feet and inches) and metric (meters and centimeters) units for the results.

Formula: The calculations are based on the following approximation:

Metric:
Total Length (meters) = 142.5 / Frequency (MHz)
Each Leg (meters) = Total Length / 2

Imperial:
Total Length (feet) = 468 / Frequency (MHz)
Each Leg (feet) = Total Length / 2

Important Considerations:

• These calculations provide a starting point. The actual resonant frequency of the antenna can be affected by factors like the height above ground, the diameter of the wire used, and nearby objects.
• For precise tuning, it is recommended to use an antenna analyzer to measure the Standing Wave Ratio (SWR) and make adjustments to the antenna length as needed.
• Always observe safe practices when working with antennas, especially regarding power levels and heights.