Electrical & Electronics
Series & Parallel Component Calculator
Calculate equivalent resistance or capacitance for multiple components connected in series or parallel, with a circuit diagram.
Your inputs
Your results
- Equivalent value
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- Component count
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- Minimum
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- Maximum
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Req = R1 + R2 + …For readability, the diagram shows the first eight components and the remaining count. All components are included in the calculation.
Combine resistors or capacitors in one series or parallel group
Find the equivalent value of a group of ideal resistors or capacitors. Choose one component type and one connection for the entire list, then compare the result with the smallest and largest entered values. The diagram helps check the chosen arrangement; mixed networks must be reduced in separate stages. Tolerance, voltage rating and power dissipation are not calculated.
Step by step
- Choose resistors or capacitors, then series or parallel. Enter each component's value and unit in its own row; add or remove rows to match the group you are calculating.
- Check the units before reading the equivalent value. Changing a row's unit converts its current valid value rather than simply attaching a different unit to the same number.
- Review the equivalent value, component count and diagram. For a mixed network, calculate a simple subgroup first, then enter its equivalent value as one component in the next stage.
Settings and limits
- Opposite combination rules
- Series resistors and parallel capacitors add directly. Parallel resistors and series capacitors use the sum of reciprocals. With positive values, the reciprocal combination is smaller than the smallest component; the direct sum is larger than each individual component when the group contains more than one.
- Rows and diagrams
- The tool accepts up to 50 components and includes every row in the calculation. The diagram displays at most 8 components, so use the component count and list to confirm a larger group. Separate resistor and capacitor lists are retained while you switch component type.
- Zero values and idealization
- Nonnegative values are accepted. A zero in a reciprocal combination makes the equivalent value zero in this ideal model; a zero in a direct sum adds nothing. Real components have parasitic effects and ratings that this arithmetic does not check.
Worked example
Use two resistor rows: 100 Ω and 220 Ω. Compare series and parallel connections. Then choose capacitors and enter 100 nF and 220 nF to compare the corresponding capacitor results.
| R1 | R2 | R1 + R2 | R1 ∥ R2 |
|---|---|---|---|
| 100 Ω | 220 Ω | 320 Ω | 68.75 Ω |
The resistors give 320 Ω in series and 68.75 Ω in parallel. The capacitors give 68.75 nF in series and 320 nF in parallel. The same numeric pair demonstrates why you must choose the component type as well as the connection.
Questions and troubleshooting
Can I enter a mixture of series and parallel connections?
Each calculation applies one connection to every listed component. Reduce an identifiable subgroup, replace it with its equivalent and repeat for the next stage. The tool does not analyze an arbitrary circuit topology from a flat list.
Why did changing the unit leave the result unchanged?
A valid value is converted to the newly selected unit, preserving the same physical resistance or capacitance. To change the component itself, edit the value after choosing the intended unit. Check an invalid entry manually before relying on a unit conversion.
Why are the results blank?
At least one row is required, and each value must be a supported nonnegative quantity. Check for missing values, negative entries or an incompatible unit suffix. Restore a valid row or reset the list, then confirm the selected component type.