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.
Frequently asked questions
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.