DELTALINK / RF
Parabolic Dish Gain Calculator
Estimate aperture gain, size a reflector, and compare frequency and efficiency assumptions.
Free. No registration. Values stay in your browser unless you choose to share a link.
The default chart spans center frequency ±7.5%: a visualization assumption, not a physical antenna bandwidth limit. Override it in Advanced settings.
Frequency comparison
Chart data and units
Engineering notes, formulas & examples
Formula and units
λ = c/f; G = 10log₁₀[η(πD/λ)²]; D = (λ/π)√(10^(G/10)/η)
D is diameter in metres; f is frequency in Hz; η is efficiency as a fraction. c = 299,792,458 m/s. Gain is dBi, not dBm.
Worked example
At 5.8 GHz, D = 0.6 m and 50% efficiency, gain is approximately 28.23 dBi and wavelength 51.69 mm.
Assumptions and limitations
Feed illumination, spillover, blockage, surface accuracy and losses affect aperture efficiency. Curves assume each selected efficiency stays constant; real efficiency can change with frequency. This is not a verified product specification.