Resistor Color Code Calculator
Decode a 4-band resistor color code.
About this tool
Decode a standard 4-band resistor's color code into its resistance value and tolerance. The first two bands give the significant digits, the third is a multiplier, and the fourth is the tolerance.
Key Features
- Standard 4-band resistor decoding
- Covers all standard digit, multiplier and tolerance colors
- Shows resistance in an easy-to-read unit (Ω/kΩ/MΩ)
How to Use
- Select each band's color, reading left to right on the resistor.
- Click Decode Resistor.
Benefits
- Quickly identify a resistor's value without a multimeter
- Check your reading of a resistor against the calculated value
- Learn the standard color code system
Frequently Asked Questions
Start from the band closest to one end of the resistor — the tolerance band (often gold or silver) is usually set slightly apart from the others and should be read last, on the right.
5- and 6-band resistors use three significant-digit bands instead of two, for higher precision — this calculator is built for the more common 4-band case.