Resistor Color Code Decoder
Choose the color bands to read a resistor’s value and tolerance.
Read any resistor at a glance
Resistor values are printed as color bands, and decoding them by eye is slow and error-prone. Pick the colors here and this reads out the resistance and tolerance, handling both 4-band and 5-band resistors.
Brown-black-red-gold, for instance, decodes to 1 kΩ ±5%. The tool multiplies the significant digits by the band’s power of ten and applies the tolerance band, formatting the result in ohms, kΩ, or MΩ.
Accurate and private
The color-to-value mapping is built in and applied in your browser, so it responds instantly with nothing uploaded.
Frequently Asked Questions
How do the bands work?
The first bands are significant digits, the next is a power-of-ten multiplier, and the last is tolerance. A 4-band resistor has two digit bands; a 5-band has three.
What do the colors mean?
Black is 0 through white is 9 for digits; gold and silver are fractional multipliers; gold (5%) and silver (10%) are common tolerances.
Does it round to standard values?
It shows the exact decoded value; real resistors come in standard E-series values close to that figure.
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