Antenna Near Field & Far Field Distance Calculator
Calculation
Enter antenna dimension and frequency. Press Calculate to update wavelength and near/far-field distances.
Antenna Dimension, D
Frequency
Output distance unit
Wavelength, λ
— m
Reactive Near-Field
≤ — m
Radiating Near-Field
≤ — m
Far-Field
≥ — m
Formulas
\[
\begin{aligned}
&\textbf{Reactive Near Field} \le 0.62\sqrt{\frac{D^{3}}{\lambda}}\\[6pt]
&\textbf{Radiating Near Field} \le \frac{2D^{2}}{\lambda}\\[6pt]
&\textbf{Far Field} \ge \frac{2D^{2}}{\lambda}\\[10pt]
&\lambda=\frac{c}{\mathrm{Freq}}
\end{aligned}
\]
Definitions
D Largest antenna dimension (meters)
λ Wavelength (meters)
c Speed of light \(= 299{,}792{,}458\ \text{m/s}\)
Freq Frequency (cycles per second, Hz)