This tool calculates the Quality Factor of a Capacitor. As the name suggests the higher the numerical value, the better the quality of the component.

## Formula

**Q = 1/(2π*f*C*ESR)**

where,

**f**= Frequency**C**= Capacitance**ESR**= Equivalent Series Resistance

The Dissipation Factor **DF = 1/Q**.

## Background

The quality factor **Q**, is a dimensionless number that is equal to the capacitor’s reactance divided by the capacitor’s equivalent series resistance (ESR).

**Q = X _{C}/ESR**

An ideal capacitor has an ESR = 0. In that case Q = ∞. However in practice the series resistance is never zero. Ideally this value is kept as small as possible to minimize losses.

Typical quality factor values of a Capacitor advertised as having High Q are shown below.

Using the calculator above, a capacitance of 1000 pF, Frequency 1 kHz and ESR of around 16 Ω gives a Q = 10,000.

**Example Calculation**

A capacitor with an ESR of **0.2 Ω**, capacitance **10 μF** and Frequency 120 Hz has a Quality Factor **Q=663**.