Dipole Calculator

Find the length of a half-wave dipole antenna.

Total length 1.43

Each leg 0.715

Formula: length ≈ 143 ÷ f(MHz) metres

Step-by-step with your numbers:

1. Values used:

2. Frequency = 100 MHz

4. Total length = 1.43

5. Each leg = 0.715

Did we solve your problem today?

A half-wave dipole is cut to roughly half the wavelength, with a velocity-factor correction.

The math behind it

Total length ≈ 143 ÷ f(MHz) in metres (≈ 0.95 × half-wavelength to allow for end effects). Each leg is half of that.

100 MHz → about 1.43 m total (0.715 m per leg).

Why not exactly half a wavelength?

End-effect capacitance makes the resonant length slightly shorter.