Free Online Tool
Series and Parallel Resistor Calculator
Calculate the equivalent resistance of multiple resistors connected in series or parallel.
The result will appear here.
How to Use
- Choose series or parallel mode.
- Enter resistor values separated by new lines or commas and select a unit.
- Review the equivalent resistance in Ω, kΩ, and MΩ.
Examples
- Calculate 1kΩ, 2kΩ, and 3kΩ in series
- Check that two 10kΩ resistors in parallel equal 5kΩ
Calculation and Conversion Notes
Series equivalent resistance is calculated as `Rtotal = R1 + R2 + R3 + ...`. Parallel equivalent resistance is calculated as `1 / Rtotal = 1/R1 + 1/R2 + 1/R3 + ...`. Parallel calculations cannot use 0Ω or negative resistance values.
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