Q Factor Calculator
Calculate the Quality Factor of a coil or capacitor with the Q Factor Calculator and learn on the go with the integrated live example
The quality factor of a resonator is related to the bandwidth and is a measure of its resonant frequency response. High Q resonators have a narrow bandwidth so will only respond to and work on a narrow band of frequencies. This makes them more difficult to tune, but they perform better at resonance than low Q resonators. For example, a coil with a high Q value will have greater resonant voltage rise than a low Q coil.
The formula for calculating the Q factor of an inductor or capacitor is:
Where
Q = Quality Factor
X = Reactance in ohms
R = Resistance in ohms
Example 1: Find the Q factor of an inductor that has a inductive reactance of 2400 Ohms and series resistance of 3.5 Ohms
Example 2: Find the Q factor of a capacitor that has a capacitive reactance of 4000 Ohms and series resistance of 5 Ohms
Use the calculator below to see a live example.
Using the Q Factor Calculator
Reactance: Enter the inductive or capacitive reactance
Resistance: Enter the series resistance
Units: You can choose your preferred units of measurement through selecting the units cells and clicking the arrow to display a list of available options
Learn As You Go: This feature displays a live example of how to calculate Q Factor using the figures that you enter
Reference: ARRL – The Radio Amateur’s Handbook
Additional information
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