Parallel Circuit Resistor Calculator
Parallel Resistor Calculator works out Equivalent resistance and Parallel bank from Resistances and Supply voltage across the network. The default figures on this page give equivalent resistance of 5.000000 ohm; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
3 steps
- 2 resistor(s): 10 ohm, 10 ohm.
- 1/R = 1/10 + 1/10 = 0.2 S, so R = 5 ohm
- No supply voltage given, so currents and power are not reported.
Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
3 sources
What the Parallel Resistor Calculator calculates
Computes the equivalent resistance of resistors in parallel, in series, or as a parallel bank in series with others, plus the conductance and the branch currents at a chosen supply voltage.
How to use this Parallel Resistor Calculator
Enter Resistances and Supply voltage across the network. Equivalent resistance updates as you type. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Equivalent resistance, Parallel bank and Series total of every resistor.
The method follows Kirchhoff's circuit laws: series resistances add, parallel conductances add, IEC 60050, International Electrotechnical Vocabulary and Researched engineering contract R943 (PARALLEL-R).
What you can compare
Change one input at a time to see how it affects Equivalent resistance, Parallel bank and Series total of every resistor. The inputs you can vary are Resistances and Supply voltage across the network.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
How do you calculate resistors in parallel?
Computes the equivalent resistance of resistors in parallel, in series, or as a parallel bank in series with others, plus the conductance and the branch currents at a chosen supply voltage. Open “How this is worked out” beside the result to see each step for your own figures.
How do I calculate the total resistance of a parallel circuit using a calculator?
It needs Resistances and Supply voltage across the network. Nothing else is required, and the figures stay in your browser.
How to calculate 4 resistors in parallel?
The result gives Equivalent resistance, Parallel bank, Series total of every resistor, Equivalent conductance, Resistors and Total current, each labelled with its unit so the figure can be read on its own.
How to calculate the resistance of resistors?
The page opens with worked default figures: equivalent resistance of 5.000000 ohm. Replace them with your own and every figure updates as you type.
What information do I need for the Parallel Resistor Calculator?
You need Resistances and Supply voltage across the network. The page opens with default figures that give equivalent resistance of 5.000000 ohm, so you can see the scale before entering your own.
What does this Parallel Resistor Calculator show?
It shows Equivalent resistance, Parallel bank, Series total of every resistor, Equivalent conductance, Resistors, Total current, Total power and Current in each resistor, with the working and any warnings for your entries.