Skip to content
Free calculators and practical guides for smarter home projects.
DIY Cost Tools

DIY Cost Tools

LC Resonant Frequency Calculator

Find the ideal resonance frequency of one inductor and one capacitor. Enter millihenries for L and nanofarads for C; mixing microfarads and nanofarads would change the answer substantially. The frequency result is cycles per second, while angular frequency is radians per second. This gives an ideal reference for an LC circuit, not a measured resonance of a complete real assembly with losses and parasitic components.

Enter every field, including explicit zeros when permitted. Decimal and scientific notation are accepted; commas, fractions and blanks are rejected. Each input must be finite and no larger than 1 billion in absolute value. Observe the units and positive-value requirements below.

Ideal resonant frequency (Hz)5032.92121
Angular frequency (rad/s)31622.7766

How to use this calculator

  1. Match your inputs to the stated circuit model and field labels.
  2. Convert your quantities to the units printed next to each field.
  3. Select Calculate, or press Enter, and read the labeled results.

Formula and method

ω0 = 1/√(LC); f0 = 1/(2π√(LC)). Convert mH to H and nF to F first.

The calculation runs in your browser. After changing an input, select Calculate again. Invalid inputs or undefined mathematical conditions hide the previous result so it cannot be mistaken for an answer to the new values.

Worked example

With L = 10 mH = 0.01 H and C = 100 nF = 0.0000001 F, LC = 10⁻⁹. The ideal frequency is approximately 5,032.92121 Hz.

Limitations and safety

Ideal-component calculation only. Component tolerance, heating, parasitic effects and frequency limits are not modeled. This output does not establish component ratings, wiring compliance or a safe circuit design. Have consequential designs checked by a qualified professional; do not use this tool as instructions for working on energized equipment. Actual resonance and bandwidth depend on the full topology, resistance, losses and stray components. No quality factor or safe operating voltage is inferred.

The fields accept signed numerical input, but positive-only component values and nonnegative time or frequency requirements are enforced by the calculation. Read each error message before changing a value. Results use floating-point arithmetic and are shown to approximately 10 significant digits; component tolerances generally do not justify using all those digits in a physical design.

Frequently asked questions

Why are frequency and angular frequency different?

Angular frequency equals 2π times ordinary frequency. They describe the same oscillation using different units.

Why are my units important?

The calculator uses exactly the units printed in the input labels. For example, a micro-unit is one millionth of a base unit, and a milli-unit is one thousandth. Entering a base-unit value into a prefixed-unit field changes the meaning of the input.

Does the answer establish a safe component rating?

No. The formula evaluates an ideal model. Ratings, tolerances, transients, installation requirements and environmental limits need a separate design assessment.

Review notes and reference

Reviewed October 3, 2026. The default worked example and an additional boundary or scaling check were tested against expected values. Validation checks included blanks, nonnumeric text and inputs outside the supported range. OpenStax University Physics formula reference provides the circuit theory behind this model. The text and worked example on this page are original.

Related calculators

Electrical calculators · Voltage Divider Calculator · Resistor Network Calculator · Capacitor Energy Calculator · Ohm’s Law Calculator · All calculators