Resistors will have either 3 or 4 bands on them. The first three bands tell you how to compute the resistance in ohms. The fourth, if present, indicates the tolerance (accuracy).

```Color   Band 1 Band 2   Band 3
gold      X      X    x   .01
silver    X      X    x   .1
Black     0      0    x   1
Brown     1      1    x   10
red       2      2    x   100
orange    3      3    x   1,000
yellow    4      4    x   10,000
green     5      5    x   100,000
blue      6      6    x   1,000,000
violet    7      7    x   10,000,000
gray      8      8    x   100,000,000
white     9      9    x    ---------

```

Band four(tolerance band code):

Gold = ±5%
Silver = ±10%
None = ±20%
Red = ±2%
Brown = ±1%

EXAMPLE
You have a resistor with bands: brown-black-red, what is it's resistance in ohms?
band one(brown) = 1
band two(black) = 0
band three(red) = 100

(band 1 & 2) * (band 3) = resistance
10 * 100 = 1000 or 1K
Therefor a resistor with bands brown-black-red would be a 1K ohm resistor. Since the fourth band is not present, it has a ±20% accuracy.