Resistor color coding is a method of identifying the value of a resistor by the colors of the bands on the resistor. The standard method of color coding uses four bands to indicate the value of the resistor. The first three bands indicate the value of the resistor, and the fourth band indicates the tolerance of the resistor.

The first band, which is located closest to the end of the resistor, indicates the first digit of the resistor value. The second band indicates the second digit of the resistor value. The third band, which is located furthest from the end of the resistor, indicates the number of zeroes to be added to the first two digits to determine the overall resistance value.

The fourth band, which is located closer to the end of the resistor, indicates the tolerance of the resistor. The tolerance tells how accurate the resistance value is. The most common tolerance values are:

For example, if a resistor has the color code brown, black, red and gold, the first digit is 1, the second digit is 0, and the number of zeroes is 2, making the resistance value of the resistor 10 x 100 ohms or 1000 ohms. The tolerance is 5% (Gold color)

It is important to note that some resistors may have additional bands, such as a fifth band for temperature coefficient, or a sixth band for failure rate. Additionally, it's also worth mentioning that some resistor manufacturers may use different color codes, so it's always best to check the manufacturer's specifications or consult a reference chart.

Electronics

Resistor Colour Code Explained