# Voltage across a Capacitor Equation, Formula, Calculation

### The voltage across a capacitor equation

As you know the capacitor stores the electricity and releases the same. Here the voltage across a capacitor V(V) in volts is equal to the capacitive reactance Xc in ohms times of the capacitor current in Amps. The capacitor voltage formula will be,

V(V) = I(A)  x Xc

Volts = Amps x capacitive reactance

Here the capacitive reactance Xc is equal to the 0.159 divided by frequency and the capacitance. Hence the voltage across the capacitor equation will be

V(V)  = 0.159 x I(A) / (f(Hz) x C(F))

### Capacitor voltage for the non-sinusoidal wave:

Capacitor voltage Vc is equal to the integration of the current I(A) in amps divided by the capacitance C(F) in Farad. The formula will be,

V = (1/C) x ∫Idt

Example:

Let us calculate the voltage across the 3-farad capacitor and the current flow is 10sin10t Amps.

The voltage across the capacitor is,

V = (1/3) ∫10*sin10t

= – 3.3 cos10t volts

Capacitor voltage formula with charge:

The voltage across the capacitor V(V) in volts is equal to the ratio between the charge Q(c) in coulomb to the capacitance C(F) in farad.

The capacitor voltage V(V) = Q(c) / C(F)