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Resistor Color Code

Convert ohms to color bands instantly with our interactive visual calculator.

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Resistor Graphic

About the Resistor Color Code Calculator

How to Read a 4-Band Resistor

Through-hole resistors use painted color bands to indicate their resistance value and tolerance. This system was developed because printing tiny numbers on small, cylindrical components was difficult and prone to wearing off. The standard 4-band system is read as follows:

  1. Band 1 (1st Digit): Represents the first significant digit of the resistance value.
  2. Band 2 (2nd Digit): Represents the second significant digit.
  3. Band 3 (Multiplier): Tells you how many zeros to add to the first two digits (or what power of 10 to multiply them by).
  4. Band 4 (Tolerance): Located slightly apart from the others, this band indicates the precision of the resistor (e.g., ±5% means the actual resistance can vary by 5% above or below the stated value).

Why use this tool?

Calculating color codes manually requires memorizing a table of colors ranging from Black (0) to White (9), plus multipliers and tolerances. This client-side tool allows makers, electrical engineers, and students to simply type in their desired resistance (like "4.7 kΩ") and instantly see the correct color bands mapped onto a CSS-drawn resistor. No server calls are made, ensuring a lightning-fast experience.