RF / Antennas

Parabolic Dish Gain Calculator

Estimate parabolic dish gain, beamwidth, wavelength, and effective aperture from frequency, diameter, and efficiency.

Frequency

Dish diameter

Aperture efficiency %

Estimated gain-- dBi 3 dB beamwidth--° Wavelength-- mm Effective aperture-- m² Ideal 100% gain-- dBi Efficiency loss-- dB

Design quantity	Value	Planning note
Diameter / wavelength	--	Electrical aperture size
Physical aperture	-- m²	Dish face area
First-null beamwidth	--°	Approx. 140 λ/D

Results assume a circular parabolic aperture in free space. Gain excludes feed-line and impedance-mismatch losses unless they are already reflected in the efficiency value.