Series & Parallel Resistance
Paste resistor values to get the total series and parallel resistance.
Combine resistors two ways
Resistors combine differently depending on how they are wired: in series their values add, and in parallel they combine reciprocally into something smaller than any single one. This tool shows both totals for a whole list at once.
For 100, 220, and 330 ohms the series total is 650 Ω, while the parallel total is about 58.8 Ω — smaller than the 100 Ω resistor, as parallel combinations always are.
Accurate and private
It sums for series and combines reciprocals for parallel across every value you enter, computing it all in your browser.
Frequently Asked Questions
How do series and parallel differ?
In series the resistances add up; in parallel the reciprocal of the total equals the sum of the reciprocals, so the parallel total is always smaller than the smallest resistor.
Can I mix many resistors?
Yes — enter as many values as you like and the tool computes both totals for the whole set.
What units are used?
Whatever unit you enter in — the totals come out in the same unit, usually ohms.
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