Interactive Parallel & Series Calculator
Calculate equivalent values for resistors, capacitors, or inductors connected in series and in parallel.
1e-6 is supported.
What this parallel and series calculator does
This tool gives you the equivalent value of multiple components connected in either series or parallel. It is useful for electronics design, homework, lab work, and quick sanity checks while prototyping. Instead of doing repetitive arithmetic by hand, you can paste your list of component values and get instant results.
The calculator supports three common component types:
- Resistors (Ω)
- Capacitors (F)
- Inductors (H)
Series vs parallel formulas
Resistors
For resistors, series values add directly:
Rseries = R1 + R2 + ... + Rn.
Parallel resistor equivalent uses reciprocals:
1 / Rparallel = 1/R1 + 1/R2 + ... + 1/Rn.
Capacitors
Capacitors are the opposite of resistors in many simple DC/steady-state equivalent calculations.
Parallel capacitance adds directly:
Cparallel = C1 + C2 + ... + Cn.
Series capacitors use reciprocals:
1 / Cseries = 1/C1 + 1/C2 + ... + 1/Cn.
Inductors
For ideal uncoupled inductors, series inductance adds directly:
Lseries = L1 + L2 + ... + Ln.
Parallel uses reciprocals:
1 / Lparallel = 1/L1 + 1/L2 + ... + 1/Ln.
How to use the calculator
- Select your component type.
- Enter values separated by commas, spaces, or line breaks.
- Set your preferred decimal precision.
- Click Calculate.
The result panel will show both equivalent series and equivalent parallel values, so you can compare configurations immediately.
Practical examples
Example 1: Resistors
If you enter 10, 22, 47 Ω:
- Series:
79 Ω - Parallel: approximately
6.37 Ω
Example 2: Capacitors
If you enter 1e-6, 2.2e-6, 4.7e-6 F:
- Series: smaller than the smallest capacitor
- Parallel: direct sum of all capacitances
Common mistakes to avoid
- Mixing units (for example, entering 10 and 10k without converting first).
- Using negative values, which are invalid for this basic equivalent model.
- Confusing capacitor and resistor formulas (they are reversed for series/parallel).
- Ignoring real-world effects such as tolerance, ESR, and temperature drift.
Final notes
This calculator uses ideal component equations. For many applications, that is perfect for quick design and estimation. If you are building precision, high-frequency, or high-power circuits, always validate with datasheets, simulation tools, and measurement on real hardware.