# RLC Resonant Frequency Calculator (f = 1/(2π√(LC)))

Compute the LC (RLC series/parallel) resonant frequency: f₀ = 1/(2π·√(L·C)). Resonant frequency is identical for series and parallel RLC; R only affects Q and bandwidth. Solves for f₀, L, or C from the other two, and returns angular resonance ω₀ and characteristic impedance √(L/C). L in H/mH/µH, C in F/µF/nF/pF, f in Hz/kHz/MHz.

> Canonical page: https://elysiatools.com/en/tools/resonant-frequency-rlc

- **Category:** Math & Numbers

- **Keywords:** resonant frequency, resonance, RLC, LC circuit, f0, 1/(2π√(LC)), angular frequency, characteristic impedance, inductance, capacitance, tuned circuit, filter, electronics, RF

## Overview

The RLC Resonant Frequency Calculator uses f₀ = 1/(2π√(LC)) to calculate resonant frequency from inductance and capacitance, or solve for L or C when the other two values are known. It also returns angular resonance ω₀ and characteristic impedance √(L/C).

## Inputs

- **Solve For** (select): Which quantity to compute: f₀ from L+C, L from f+C, or C from f+L.
- **Inductance L** (number): Required when solving for f₀ or C. Enter in the selected Inductance Unit.
- **Inductance Unit** (select)
- **Capacitance C** (number): Required when solving for f₀ or L. Enter in the selected Capacitance Unit.
- **Capacitance Unit** (select)
- **Frequency** (number): Required when solving for L or C. Enter in the selected Frequency Unit.
- **Frequency Unit** (select)
- **Decimal Places** (number)

## When to use

- Find the resonant frequency of an LC or RLC series or parallel circuit.
- Calculate the inductance needed for a target frequency and known capacitance.
- Calculate the capacitance needed for a target frequency and known inductance.

## How it works

- Choose whether to solve for frequency f₀, inductance L, or capacitance C.
- Enter the available values and select units for inductance, capacitance, and frequency.
- The calculator applies the resonance formula after converting the values to base units.
- Review the calculated result, angular resonance ω₀, and characteristic impedance.

## Use cases

- Tune RF and electronics circuits to a target frequency.
- Select an inductor and capacitor pair for a tuned LC circuit.
- Check component values used in filters and resonant networks.

## Frequently asked questions

### What formula does the calculator use?

It uses f₀ = 1/(2π√(L·C)).

### Can I solve for inductance or capacitance?

Yes. Select Inductance L or Capacitance C and enter the other two required values.

### Which units are supported?

Inductance supports H, mH, and µH; capacitance supports F, µF, nF, and pF; frequency supports Hz, kHz, and MHz.

### Is resonant frequency different for series and parallel RLC circuits?

No. The calculator uses the same LC resonant-frequency formula for both.

### What additional values are returned?

The result includes angular resonance ω₀ and characteristic impedance √(L/C).

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