Electrical Calculators

Resistor Color Code Calculator

Decode four-band and five-band resistor color markings.

Reviewed July 26, 2026 Runs locally No sign-up

Global formulaFormula-based estimate

=Your result will appear here

Enter values and calculate.

APPLICABILITY

Where this result fits

Region: Global formula
Result type: Formula-based estimate
Standards basis: IEC 60062:2016 + AMD1:2019 — Marking codes
Edition / version: Named formula or standard edition; implementation reviewed July 26, 2026

Important: Confirm equipment ratings, installation conditions, protection requirements, and the electrical code adopted where the work will be performed. Electrical safety policy

STEP BY STEP

How to use the Resistor Color Code Calculator

Choose four or five bands.
Select colors from left to right with the tolerance band last.
Decode the resistance and tolerance.
Confirm orientation and markings before installing the component.

ACCURACY & LIMITS

What to know before using the result

Colors can be difficult to distinguish on aged or overheated components.
Measure unknown resistors out of circuit when safety or accuracy matters.

HELP

Frequently asked questions

How accurate is the Resistor Color Code Calculator?

The calculator uses the formula shown on this page and keeps full numeric precision internally before formatting the result. Colors can be difficult to distinguish on aged or overheated components.

Does the Resistor Color Code Calculator upload my input?

No. The calculation or processing runs locally in your browser. UtiliNest does not receive or store the values you enter.

Can I use the Resistor Color Code Calculator on a phone?

Yes. The inputs, result controls, and explanatory content are designed for current mobile and desktop browsers.

Where does the Resistor Color Code Calculator apply?

Applicability: Global formula. Result classification: Formula-based estimate. Confirm equipment ratings, installation conditions, protection requirements, and the electrical code adopted where the work will be performed.

SOURCES

Definitions and references

Reviewed against the references below on July 26, 2026. Links open the source publisher's website. Read the source policy

IEC 60062:2016 + AMD1:2019 — Marking codes