Parallel/Series Resistor Calculator
Calculate the equivalent resistance for resistors connected in parallel or series configurations.
Resistor Configuration
Select configuration and add resistor values
Circuit Diagram:
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Series: Req = R1 + R2 + R3 + ...
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Results
Equivalent resistance for the configuration
Select configuration and resistor values, then click "Calculate Equivalent Resistance" to see results
How It Works
Series Configuration
Resistors are connected end-to-end, creating a single path for current flow.
Req = R1 + R2 + R3 + ...
The equivalent resistance is the sum of all individual resistances.
Parallel Configuration
Resistors are connected across the same voltage source, creating multiple current paths.
1/Req = 1/R1 + 1/R2 + 1/R3 + ...
The equivalent resistance is always less than the smallest individual resistance.