Resistor Color Code

Decode a 4-band resistor color code into its resistance value and tolerance.

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band 1

band 2

multiplier

tolerance

result

— output appears here —

About this tool

Pick the four colored bands of a resistor and read off its resistance and tolerance, with a live preview of the band colors, all in your browser.

How is the value calculated?

The first two bands form a two-digit number, the third band multiplies it by a power of ten, and the fourth band gives the tolerance.

Does it support 5-band resistors?

This decoder covers the common 4-band code; 5-band resistors add a third significant-figure band not handled here.