Getting Started with Intel Galileo

Appendix C. Resistor Reference

If you’re doing basic hobby electronics, you’ll typically use resistors with four color bands. The first three bands indicate resistance in ohms, according to Table C-1. The fourth band indicates tolerance, which will usually be gold (5%) or silver (10%), but could also be brown (1%) or red (2%).

The tolerance of the resistor indicates the possible amount of variance between the indicated value and the actual value of the resistor. If no tolerance is indicated, it’s assumed that it’s 20%.

Table C-1. Basic four-band resistor reference

Color	First Band	Second Band	Third Band (Multiplier)	Fourth Band (Tolerance)
Black	0	0	x1
Brown	1	1	x10	1%
Red	2	2	x100	2%
Orange	3	3	x1K
Yellow	4	4	x10K
Green	5	5	x100K
Blue	6	6	x1M
Purple	7	7	x10M
Gray	8	8
White	9	9
Gold	5%
Silver ...