This all-in-one online Resonant Frequency Calculator performs calculations using the formula that relates the inductance and the capacitance of an LC circuit to its resonant frequency. You can enter the values of any two known parameters in the input fields of this calculator and find the missing parameter.
Resonant Frequency Formula
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, is an electric circuit consisting of an inductor (L) and a capacitor (C) connected together.
If a current begins to flow in the LC circuit due to external influence, then the effect of alternate energy accumulation by the capacitor and inductor occurs. A capacitor stores energy in an electric field (E) between its plates depending on the voltage across it, while an inductor stores energy in its magnetic field (B) depending on the current through it.
Charge flows back and forth between the plates of the capacitor and through the inductor. The energy oscillates back and forth between the capacitor and the inductor, and in the case of a small internal resistance, the oscillations continue for a long time at a constant frequency, called the resonant frequency.
If the frequency of the external variable electromotive force acting on the circuit coincides with the resonant frequency of the LC circuit, then it is said that there is resonance in the system. In this case, the current in the LC circuit increases sharply.
The resonant frequency of an LC circuit is expressed by the following formula, which is used in our Resonant Frequency Calculator:
$$f = \frac{1}{2\pi \sqrt{LC}},$$
where
\(L\) is the inductance measured in the SI system in henry (H). Dimension: M·L2·T-2·I-2,
\(C\) is the capacitance measured in the SI system in farad (F). Dimension: M-1·L-2·T4·I2,
\(f\) is the resonant frequency measured in the SI system in hertz (Hz) : 1 Hz = 1 sec -1 .
LC circuits are used for generating signals at a particular frequency. They also used for picking out a signal at a particular frequency from a more complex signal. Such a circuit is called a band-pass filter. LC circuits are key components in many electronic devices, particularly radio equipment. They are used in various circuits such as oscillators, filters, tuners and frequency mixers.
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