The energy stored in a capacitor and the power dissipated can be calculated from the capacitance and voltage across it. The stored energy is essentially the integral of the charge with respect to voltage. Given here is the formula to calculate for the energy and power dissipated in the capacitor. The energy E can be calculated from the formula E = (1/2) C V2 and the power dissipated in the capacitor P can be calculated from the formula P = V x V / Q. Where, C is the capacitance and V is the Voltage.
Capacitor energy and power dissipated formula is made simple by just multiplying the double time the voltage with resistor. Also, you can click on the above calculator link to know for ease calculations.