LC Resonant Frequency Calculator

Find the resonant frequency of an LC tank circuit from the inductance and capacitance, or solve for a component to tune to a target frequency.

Resonant frequency

An inductor and capacitor together resonate at f = 1 / (2π·√(L·C)). This is the basis of radio tuning, oscillators and filters. Increasing either L or C lowers the resonant frequency.

Frequently asked questions

What is LC resonance?

An inductor and capacitor exchange energy back and forth, and at one particular frequency they reinforce each other: the resonant frequency, f = 1 / (2π·√(L·C)). It is how radios tune to a station and how many oscillators set their frequency.

What units does this use?

Inductance in microhenries (µH) and capacitance in picofarads (pF), which are the practical ranges for radio-frequency work. The tool converts internally and shows the frequency in Hz up to GHz.

How do I tune to a specific frequency?

Pick one component you have, then adjust the other until the resonant frequency matches your target. Larger L or C gives a lower frequency, smaller gives higher.