Series & Parallel Resistance Calculator
Combine up to two hundred positive resistor values in series or parallel.
What would you like to do next?
Combine a list of ideal resistor values
Paste resistance values in ohms separated by spaces, commas or lines and choose a series or parallel network. The calculator adds resistances directly for series and adds their reciprocal conductances for parallel, then reports both equivalents with the selected result highlighted. It also shows the number of accepted values and the smallest and largest resistor for a quick input review.
Account for the physical components afterward
The ideal equivalent does not include tolerance, lead and contact resistance, self-heating, voltage rating, power sharing, frequency response or a failed component. Parallel resistance will always be below the smallest included positive resistor, which is a useful reasonableness check. Verify actual components and circuit conditions before assembly or testing.
Frequently asked questions
How should I separate resistor values?
Use spaces, commas, semicolons or new lines and enter every value in ohms.
How are series resistors combined?
Their resistance values are added directly.
Why is parallel resistance below the smallest resistor?
Parallel conductances add, creating more total current paths than any one branch.