The conventional, small, monopole antenna is sometimes modified and bent into the shape of an inverted L. The inverted L antenna displays less capacitive reactance and higher radiation resistance than the monopole. Using a novel method, we derive a formula for the input impedance of the inverted L antenna. The technique involves extending the conventional Pocklington integral equation and the use of the antenna's effective length. The method can be adapted to other electrically small antennas.