Resistor color bands are an international standard standardizing the resistance value, tolerance, and sometimes temperature coefficients of axial-lead resistors. This color-coding system, defined under standard IEC 60062, relies on a series of painted rings around the resistor body to represent numerical values. Because resistors are physically small, printing numbers directly onto them is impractical, making color bands the most reliable solution. The Resistor Color Code Chart
To read a resistor, look up the band colors in the standard Resistor Color Code Guide: Digit Value Multiplier Value Tolerance Value Temperature Coefficient Black Brown Red Orange Yellow Green Blue Violet Gray White Gold Silver None
Note: You can easily memorize the base order using the popular Electronics Mnemonic Device: “Big Brown Rosters Out Yonder Grows Big Vines Gladly Welcomed” (Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White). Step-by-Step Calculation Guide Step 1: Orient the Resistor Properly
Always read a resistor from left to right. Look for the band that is printed closest to one of the metal leads—this is your first band. Additionally, the final tolerance band is often separated by a wider gap or colored in a distinct metallic shade like gold or silver. Place this tolerance band on the far right. Step 2: Extract the Significant Digits
3-Band and 4-Band Resistors: The first two bands provide your first two numerical digits.
5-Band and 6-Band Resistors: The first three bands provide your first three numerical digits. Step 3: Apply the Multiplier
Locate the next band (the 3rd band in a 4-band system, or the 4th band in a ⁄6-band system). Match its color to the multiplier column. Multiply your extracted digits by this factor to compute the base resistance value in Ohms ( Ωcap omega Resistor Color Code Calculator with Examples
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