Resonant Frequency RLC Calculator
Calculate the resonant frequency of an LC or RLC circuit and the component values to tune it.
About Resonant Frequency RLC Calculator
Resonant frequency depends on the product of L and C, so many combinations give the same frequency. The characteristic impedance √(L/C) distinguishes them and determines the current and voltage levels at resonance. Choosing L and C to hit a frequency is underdetermined, so the second constraint is usually the impedance the circuit must present.
Formula
Resonant Frequency RLC
f₀ = 1 ÷ (2π√(LC)); rearranged, C = 1 ÷ ((2πf₀)² L)
- characteristic impedance
- √(L/C), the impedance scale of the resonant circuit
Worked example
With the default values below, Resonant Frequency RLC Calculator returns Resonant Frequency of 50,329.212. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Inductanceminimum 0 H
- 0.0001 H
- Capacitanceminimum 0 F
- 0 F
- Target resonant frequencyminimum 0.01 Hz
- 50,000 Hz
Results
- Resonant Frequency
- 50,329.212 Hz
- Resonant Frequency
- 50.32921 kHz
- Capacitance Needed for the Target
- 0.000000101321 F
- Inductance Needed for the Target
- 0.0001013212 H
- Characteristic Impedance
- 31.623 ohm
Step by step
- 1Values used
- 2Resonant Frequency RLC
- 3Resonant Frequency= 50,329.212 Hz
- 4Resonant Frequency= 50.32921 kHz
- 5Capacitance Needed for the Target= 0.000000101321 F
- 6Inductance Needed for the Target= 0.0001013212 H
- 7Characteristic Impedance= 31.623 ohm
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax or fees or charges into account.
- Figures are rounded for display to 12 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Resonant Frequency RLC calculated?
f₀ = 1 ÷ (2π√(LC)); rearranged, C = 1 ÷ ((2πf₀)² L) Resonant frequency depends on the product of L and C, so many combinations give the same frequency. The characteristic impedance √(L/C) distinguishes them and determines the current and voltage levels at resonance.
Why does Resonant Frequency RLC matter?
Choosing L and C to hit a frequency is underdetermined, so the second constraint is usually the impedance the circuit must present.
What values do I need to enter?
This calculator takes 3 inputs: Inductance, Capacitance, Target resonant frequency. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.