Resistor Color Codes

Introduction

The resistance value for a resistor is generally indicated through the use of a 4 (or 3, or 5) band color code. For a typical four-band code, the first two bands tell you the first two digits of the resistance, the third band tells you how many zeros to add, and the fourth band tells you the tolerance. For a five-band color code, the first three bands tell you the first three digits of the resistance, the fourth band tells you how many zeros to add, and the fifth band tells you the tolerance.

Digit, Multiplier, and Tolerance Band Chart

Color	Color Name	Digit band	Multiplier band	Tolerance band
	Black	0	1
	Brown	1	10	± 1%
	Red	2	100	± 2 %
	Orange	3	1000
	Yellow	4	10,000
	Green	5	100,000	± 0.5 %
	Blue	6	1,000,000	± 0.25 %
	Violet	7	10,000,000	± 0.10 %
	Gray	8	100,000,000	± 0.05 %
	White	9	1,000,000,000
	Gold		0.1	± 5 %
	Silver		0.01	± 10 %
	None			± 20 %

Examples

Four-band Resistor

A resistor that has bands (starting from the band on the part of the resistor with the largest radius) of blue-gray-brown-gold will be:

\( \mbox{blue }\mbox{ gray }*\mbox{ brown }\pm\mbox{ gold} \)

resistor, or 68 * 10 = 680±5% Ω.

Five-band resistor

A yellow-violet-red-white-silver resistor would be:

\( \mbox{yellow }\mbox{ violet }\mbox{ red }*\mbox{ white } \pm \mbox{ silver } \)

or 472 * 1000000000 = 472±10\% GΩ.

Note that the same value resistor will have a different multiplier band color in the four-band scheme than in the five-band scheme. A 1 kΩ resistor will be brown-black-red-TOL in the first case and brown-black-black-brown-TOL in the second.

Questions

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External Links

• Wikipedia page on Electronic color code
• Graphical resistance calculator by Danny Goodman