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Series Resistance Calculator

Estimate series resistance from number of bands, 1st band color, 2nd band color with the Series Resistance Calculator.

Choose a resistor workflowDecode color bands, combine resistor networks, or calculate conductor resistance.
6 options
SERIES RESISTANCE320 Ω

R = R₁ + R₂ + R₃ + R₄

Estimate based on the values shown
MethodColor value = significant digits × 10^multiplier; parallel R = 1/Σ(1/R); conductor R = L/(σπ(d/2)²). List modes accept up to ten editable resistor values; conductor length additionally supports millimeters.

Before you use the result

Check the entered units and assumptions before using the result for purchasing, construction, engineering, or safety decisions.

Sources

CALCULATOR GUIDE

How to use the Series Resistance Calculator

Estimate series resistance from number of bands, 1st band color, 2nd band color with the Series Resistance Calculator. It includes Resistor color code, Parallel resistor, Resistors in series, Resistance of a Conductor, Parallel resistor list, Series resistor list workflows, so choose the one that matches the values you actually know. Use it to check a practical estimate, paying close attention to the selected units and assumptions.

Step by step

  1. For the Series Resistance, enter number of bands, 1st band color, 2nd band color, 3rd band color, multiplier exponent. Keep each value in the unit displayed beside its field.
  2. Review the selected Series Resistance workflow and inputs, then read series resistance in the result panel.
  3. Change one Series Resistance assumption at a time to compare scenarios. Use Reset to restore this tool's worked example values.

How the calculation works

Color value = significant digits × 10^multiplier; parallel R = 1/Σ(1/R); conductor R = L/(σπ(d/2)²). List modes accept up to ten editable resistor values; conductor length additionally supports millimeters.

Worked example

In the Series Resistance worked example, number of bands 4, 1st band color Brown, 2nd band color Black, 3rd band color Black produces series resistance of 320 Ω. R = R₁ + R₂ + R₃ + R₄. Review the displayed units before comparing the result.

Understanding the result

The Series Resistance reports series resistance. Use it to check a practical estimate, paying close attention to the selected units and assumptions. Check the entered units and assumptions before using the result for purchasing, construction, engineering, or safety decisions.

How to check the answer

Check the Series Resistance result by reversing the conversion or recomputing series resistance from number of bands, 1st band color, 2nd band color. For construction, electrical, weather, or purchasing decisions, compare the result with the applicable specification or professional guidance.

Common questions

What does the Series Resistance calculate?

Estimate series resistance from number of bands, 1st band color, 2nd band color with the Series Resistance Calculator.

Which Series Resistance inputs have the biggest effect?

series resistance responds directly to number of bands, 1st band color, 2nd band color, 3rd band color, multiplier exponent. Change one input while holding the others constant to see its effect.

Is the Series Resistance result exact?

Check the entered units and assumptions before using the result for purchasing, construction, engineering, or safety decisions. Recheck number of bands, 1st band color, 2nd band color and use series resistance only for a decision where that level of precision is appropriate.

Formula tests, limits, sources, and guide registry updated September 1, 2026.
INTERPRET THE RESULTRead the other guideCheck assumptions, limitations and comparison methods →