Capacitive Reactance Calculator

What capacitive reactance measures

Capacitive reactance is a capacitor's frequency-dependent opposition to alternating current, measured in ohms just like resistance, but unlike resistance it changes with frequency instead of staying fixed.

Worked example

For a 10uF capacitor at 60Hz (standard AC mains frequency):

Xc = 1 / (2π x f x C) = 1 / (2π x 60 x 0.00001) = 265.26 ohms

Frequency	Reactance (10uF)
60 Hz	265.3 ohms
1,000 Hz	15.9 ohms
100,000 Hz	0.16 ohms

As shown above, reactance drops sharply as frequency increases - this is why capacitors are used in filter circuits to block low frequencies while letting high-frequency signals pass through with little opposition.