Electronic Components
Series Capacitor Calculator
Series Capacitor helps you find equivalent capacitance from capacitor C1 and capacitor C2. The page keeps the arithmetic visible so you can check the result against the original measurements.
Enter values for Equivalent capacitance
Replace the examples with values from the same case.
Understanding the equation
This page evaluates Ceq = C1C2 ÷ (C1 + C2). The entered quantities are Capacitor C1 and Capacitor C2.
The initial scenario returns 6.88 µF. Re-enter field data before using the answer in a design or comparison.
Calculate equivalent capacitance from capacitor C1 and capacitor C2. For the companion equivalent capacitance calculation, open Parallel Capacitor Calculator.
Sensitivity check
Change Capacitor C1 from 10 µF to 12 µF and preserve the rest of the case. This moves the answer from 6.88 µF to 7.76 µF.
This isolates one variable; a real system may change several at once.
Input notes
Record tolerance, bias point, duty cycle, and junction temperature. A source note beside each entry makes the result reproducible.
A denominator entry cannot be zero. Use the displayed unit for every field and document conversions separately.
- Capacitor C1
- Default example: 10 µF. Enter capacitor C1 in µF.
- Capacitor C2
- Default example: 22 µF. Enter capacitor C2 in µF.
Checks that catch bad inputs
Mixing nominal and measured data is a common source of error.
Verify sign, scale, and physical meaning before accepting the number.
What the number means
The calculated Equivalent capacitance is meaningful only with its input conditions attached. Compare it with minimum, nominal, and worst-case component values.
Label alternate cases rather than overwriting the baseline.
Practical limits
Voltage sharing depends on leakage and tolerance.
Outside the entered variables, consider parasitics, layout inductance, tolerance stack-up, switching edges, and thermal resistance. Resolve material omissions before selecting a standard size or rating.
Record tolerance, bias point, duty cycle, and junction temperature.
Common questions before using the result
What data should go into Series Capacitor?
Measured and rated values can represent different states. Use data-sheet values at the intended voltage, current, frequency, and temperature.
What assumptions affect Equivalent capacitance?
Voltage sharing depends on leakage and tolerance. A broader review should include pulse ratings, frequency behavior, package temperature, and layout.
Why might a second instrument give another answer?
First confirm that the measurements match the equation. Then review bias dependence, ESR, leakage, saturation, and self-heating.
Can I change several inputs at once?
Change one uncertain entry at a time and preserve the baseline. Use data-sheet values at the intended voltage, current, frequency, and temperature.
Is the result a code-compliant design value?
Use the number as one check, then review minimum, nominal, and worst-case component values.
When should I round equivalent capacitance?
Keep full precision while transferring equivalent capacitance; round only at the final reporting or selection step.