Capacitors

A capacitor stores charge $Q=C\cdot U$ and energy in the electric field:

$E=\tfrac12 C U^2=\tfrac12 Q U=\frac{Q^2}{2C}$

When connecting capacitors, the rules are the opposite of those for resistors:

$\text{parallel: } C=\sum C_i\qquad \text{series: } \frac{1}{C}=\sum\frac{1}{C_i}$

So in parallel the capacitances add up (like the areas of the plates), and in series the equivalent capacitance is smaller than the smallest capacitor. The calculator computes the equivalent capacitance of the arrangement as well as the charge and energy of a single capacitor.