What this calculates
A charged capacitor stores electrical energy in the electric field between its plates. This calculator finds that stored energy from the capacitance and the voltage it’s charged to.
The formula
The energy stored is E = ½ × C × V², where C is capacitance in farads and V is voltage in volts. This calculator also computes the stored charge, Q = C × V.
This calculator is for general electronics and physics education.
Last reviewed August 2026