Series / Parallel R·C·L Calculator
Compute the equivalent value of resistors, capacitors, or inductors wired in series and parallel.
Input
ℹ R & L: series = sum, parallel = 1/Σ(1/x). C is the opposite (series = 1/Σ(1/x), parallel = sum).
Results
Component Count—
Series Equivalent—
Parallel Equivalent—
💡 Usage & Formula
Enter two or more component values separated by commas. The equivalent uses the same unit as the inputs.
- Resistors / Inductors — Series:
R = R₁ + R₂ + …· Parallel:1/R = 1/R₁ + 1/R₂ + … - Capacitors (reversed) — Series:
1/C = 1/C₁ + 1/C₂ + …· Parallel:C = C₁ + C₂ + …
When you need it: Reducing a network of resistors, capacitors or inductors to a single equivalent value when hitting a non-standard value or checking a combination.
Worked example: Two 10 kΩ in parallel = 5 kΩ; in series = 20 kΩ. Capacitors are the mirror image: two 100 nF in series = 50 nF, in parallel = 200 nF. Parallel resistors follow 1/Rt = Σ 1/Ri.
Tips & gotchas:
- Resistors and inductors combine the same way (series adds); capacitors are reversed (parallel adds).
- N equal values in parallel give value/N — a quick way to make an odd value from stock parts.
- A parallel resistance is always smaller than the smallest resistor in the group.
- Paralleling to hit a value multiplies your tolerance error — two 5% parts don't make a 1% result.
📖 References:
Series and parallel circuits (Wikipedia)