Capacitors in Series Calculator

Capacitors in series share the same charge but split the voltage. The equivalent capacitance is always less than the smallest individual capacitor — opposite to resistors in series.

⚡ Circuits📐 1/C = 1/C₁ + 1/C₂🔋 Capacitance

C₁ (μF)

C₂ (μF)

C₃ (μF) optional

C₄ (μF) optional

Please enter valid values.

Formula & Reference

Variable	Symbol	Formula	Units
Series Total	1/C_eq	1/C₁ + 1/C₂ + 1/C₃	F
Two Caps	C_eq	C₁C₂/(C₁+C₂)	F
Charge	Q	Same on all capacitors	C
Voltage	V_total	V₁ + V₂ + V₃	V

Step-by-Step Examples

Example 1

Two Caps

10 uF and 20 uF in series.

1/C = 1/10 + 1/20 = 0.1 + 0.05 = 0.15
C = 1/0.15 = 6.67 uF

✓ 6.67 uF — less than 10 uF (the smallest)

Example 2

Three Caps

4 uF, 6 uF, and 12 uF in series.

1/C = 1/4 + 1/6 + 1/12 = 0.25+0.167+0.083 = 0.5
C = 2 uF

✓ 2 uF total

Example 3

Equal Caps

Four 20 uF capacitors in series.

1/C = 4 * (1/20) = 0.2
C = 5 uF = 20/4

✓ 5 uF — n equal caps in series: C/n

Real-World Applications

🔋

Voltage Division

Series caps split voltage across them inversely proportional to capacitance.

📻

Filter Circuits

Series capacitors in AC circuits form high-pass filters.

⚡

High Voltage Rating

Series caps can handle higher voltages than a single cap rated for the same total voltage.

🧪

Charge Storage

Series configuration reduces total capacitance but useful for voltage tolerance.

Common Mistakes to Avoid

⚠️

Result always less than smallest

Series combination always reduces capacitance. If your answer is larger than any individual cap, you have made an error.

⚠️

All share same charge

In series, charge Q is identical on every capacitor. Voltage splits inversely as V = Q/C.

⚠️

Confusing with parallel

Parallel caps ADD capacitances. Series caps have RECIPROCAL addition. Opposite of resistors.

Frequently Asked Questions

Why is series capacitance less than any single cap? ▾

Each added capacitor splits the total voltage, reducing the charge stored for a given total voltage. Less charge at same voltage means less capacitance.

What voltage does each capacitor see? ▾

V_i = Q/C_i. Smaller capacitors get higher voltage. Always check that no individual cap is over its voltage rating.

How does series compare to parallel? ▾

Series: 1/C = sum(1/Ci), same Q, split V. Parallel: C = sum(Ci), split Q, same V. Opposite behaviors.

When would you use series connection? ▾

To achieve a lower effective capacitance, or to distribute high voltage across multiple lower-rated capacitors.

What is the Q factor for series capacitors? ▾

The charge Q is the same on all capacitors in series because they form a chain — charge cannot accumulate at junction nodes.

Related Physics Calculators

Formula Explorer connections

Interpretation: This formula links charge, voltage, current, resistance, capacitance, power or circuit time response. Assumption: Confirm DC versus AC conditions, RMS versus peak values, component topology and steady-state versus transient behavior. Ideal components may be assumed.

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