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.
FAQ
Does Series and Parallel Resistor Calculator save my input?
No. Your input is not stored on a server. Supported actions run in your browser.
Can I use it on mobile?
Yes. The pages are responsive and work on desktop and mobile browsers.
Can I rely on the result?
Use the result as a quick reference. Important work should be checked separately.