Resistor Color Codes Explained Easily

The tiny cylindrical resistors used in electronic circuits use color banding to show their resistance value. Manufacturers use four such color bands on the resistor body. Each band indicates a specific value. Not only the color of the band, but also the sequence or positions of the bands determines the overall resistance value of the resistor.

From left hand side, first two colors imply the decimal digit values of the resistance. The third one tells us the multiplier value, the powers of 10. Fourth and last one at extreme right side indicates the tolerance of the resistance value.

The table below shows the meaning of each color and their implication.

Example of Four Band Resistor

For example, suppose the first color band on a resistor is brown. That indicates the first digit of the resistance value will be 1. The second color band from the left is yellow. That means the second digit of the resistance value is 4.

The next or third color band is green. That implies the multiplier will be $10^5$. Say, here the fourth and extreme right band is golden. That means the tolerance of this value is $\pm 5\%$.

Therefore, the value of the resistance of the resistor will be

$$14 \times 10^5 \ \Omega \ \pm 5\%$$

Example of Three Band Resistor

Another thing, sometimes there is no silver or gold band provided as fourth band of the resistor. In other words, there is no fourth band present on the resistor. In that case, we directly consider the tolerance of the resistance value will be $\pm 20\%$±20%.

Suppose in our previous resistor there are only three color bands. These are the same as in our previous case, i.e. brown, yellow and green.

That means the value of the resistance of the resistor will be the same. However now the tolerance of the value will be $\pm 20\%$ instead of $5\%$ unlike in the case of golden fourth band.

So, we can write value of the resistance as$$14 \times 10^5 \ \Omega \ \pm 20\%$$