To find the reactance of a capacitor at a frequency, enter the capacitor’s value and a frequency. To find the value of a capacitor that has the specified reactance at a given frequency, enter the reactance and a frequency. To find the frequency at which a given capacitance has the specified reactance, enter the capacitance and reactance.

The equations used to find the capacitance and reactance are:

Remember that although the reactance value carries units of Ohms (Ω), and the reactance value can be used to find the current though a capacitor for a given voltage, the reactance value cannot be used in combination with other reactances unless they are treated as an impedance.