How the Resistor Calculator works.
series: Rₜ = ΣR; parallel: Rₜ = 1 ÷ Σ(1/R)Enter 1–100 positive resistance values in ohms, separated by commas, spaces, or line breaks.
Worked example for the Resistor Calculator.
Resistors of 100 Ω and 220 Ω total 320 Ω in series and approximately 68.75 Ω in parallel.
How to read this result.
The result combines a list of positive resistance values using either the series sum or the reciprocal parallel formula.
How this tool gets the answer
series: Rₜ = ΣR; parallel: Rₜ = 1 ÷ Σ(1/R). Enter 1–100 positive resistance values in ohms, separated by commas, spaces, or line breaks. The result combines a list of positive resistance values using either the series sum or the reciprocal parallel formula.
A useful example
Resistors of 100 Ω and 220 Ω total 320 Ω in series and approximately 68.75 Ω in parallel. A quick way to verify the calculation is: For series, add every resistance. For parallel, add each reciprocal and invert the total; the parallel result must be below the smallest branch.
What the result tells you
The result combines a list of positive resistance values using either the series sum or the reciprocal parallel formula. All entered values are ohms. Convert kilo-ohms by multiplying by 1,000 and megaohms by multiplying by 1,000,000 before entry.
Where the answer can go wrong
Every list item must be a finite positive number; empty items, zero-ohm branches, negative values, and more than 100 components are rejected. Nominal resistance does not model component tolerance, temperature coefficient, frequency-dependent impedance, power rating, or wiring resistance.
Privacy and practical use
The calculation runs locally in your browser and FigureNest does not send the entered values to a calculation service. Keep the source value and its unit with any result you save so you can reproduce the calculation later.
Inputs and edge cases to check.
Every list item must be a finite positive number; empty items, zero-ohm branches, negative values, and more than 100 components are rejected.
What this tool does not include.
Nominal resistance does not model component tolerance, temperature coefficient, frequency-dependent impedance, power rating, or wiring resistance.
Reference guidance and methodology.
Resistor Calculator questions.
What does the Resistor Calculator do?
Calculate equivalent resistance for series or parallel resistor networks.
How can I check the result?
For series, add every resistance. For parallel, add each reciprocal and invert the total; the parallel result must be below the smallest branch.
Which units and assumptions matter?
All entered values are ohms. Convert kilo-ohms by multiplying by 1,000 and megaohms by multiplying by 1,000,000 before entry. Nominal resistance does not model component tolerance, temperature coefficient, frequency-dependent impedance, power rating, or wiring resistance.
Are the entered values sent or stored?
No. The calculation runs locally in your browser and FigureNest does not send or store calculator inputs.