Understanding Resistor Color Codes

Resistors are fundamental electronic components used to control the flow of electrical current in a circuit. Because resistors are often very small, printing their resistance value directly on their body can be difficult to read. To solve this, manufacturers use a standardized color-coding system defined by IEC 60062.

How to Read a 4-Band and 5-Band Resistor

To use this resistor color code calculator with steps, you first need to identify the number of bands on your component. Most standard resistors have 4 bands, while high-precision resistors typically have 5 bands. The bands are read from left to right, starting with the band closest to one of the leads.

4-Band Resistors: The first two bands represent the significant digits. The third band is the decimal multiplier, and the fourth band indicates the tolerance (how much the actual resistance might vary from its stated value).

5-Band Resistors: These offer higher precision. The first three bands represent the digits, the fourth is the multiplier, and the fifth is the tolerance.

Standard Color Table

Each color corresponds to a specific numerical value: Black (0), Brown (1), Red (2), Orange (3), Yellow (4), Green (5), Blue (6), Violet (7), Grey (8), and White (9). Multipliers range from 1 ohm (Black) to 10 Gigaohms, while common tolerances are Gold (5%) and Silver (10%).

Frequently Asked Questions

What is the tolerance band? The tolerance band indicates the precision of the resistor. For example, a 100-ohm resistor with a 5% tolerance (Gold) can range anywhere from 95 to 105 ohms.

Why do I read from left to right? Usually, the tolerance band (Gold, Silver, or a wider gap) is placed on the right side to help you orient the resistor correctly.