Capacitor Calculator
Calculate total capacitance for capacitors in series or parallel, and the energy stored in a charged capacitor.
Combined capacitance
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Energy stored —
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How it works
Series: 1/C = 1/C₁ + 1/C₂; parallel: C = C₁ + C₂; energy = ½CV²Frequently Asked Questions
How do capacitors combine in series vs parallel?
Parallel capacitance simply adds (like resistors in series): two 100µF capacitors in parallel give 200µF. Series capacitance behaves like parallel resistors — the reciprocal sum — so two 100µF capacitors in series give only 50µF, always less than the smallest individual value.
Why does series capacitance decrease?
In series, the same charge appears on each capacitor's plates, but the voltage divides between them — since C = Q/V, spreading voltage across more capacitors for the same charge lowers the effective combined capacitance.
How do I calculate energy stored in a capacitor?
Energy = ½ × C × V²: a 1000µF capacitor charged to 12V stores about 0.072 joules. Doubling the voltage quadruples the stored energy, since voltage is squared in the formula.