Resistor Color Coding System Explained: Calculator and Example

Resistor color coding is the representation of the rating of components by marking different color over the components. The coding was introduced in the 1920’s and then standardized in 1952 by IEC.

Why Use resistor Color coding?

Originally the color coding was meant to use for fixed resistors, capacitor, inductor and diodes. Because printing color bands were not easy and cheap on small components at that time. Advancement in printing technology make it easier to print practically anything over these tiny electronic components but the convention remains.

resistor color code calculator:

First Band Color

Second Band Color

Third Band Color

Fourth Band Color

Final Resistance

Color Coding chart:

Each color has its own value starting from 0 to 9. The coding has also room for the tolerance in the rating. Tolerance is the percentage of error in resistance value. The resistor color code chart is given below.

Resistor color chart

Resistor Value:

Colors are banded around the component most commonly resistors. There is typically 4 color circle around the resistor. Starting from left, first two color represents first and second digits. The third one shows the multiplier using scientific notation ($\times 10^{\alpha }$). Finally, the fourth color band shows the tolerance in percentage.

4 band resistor color code format

Observing the diagram, you may notice the spacing between the last two color bands is different which is the right side of the resistor.

Resistors manufactured defense purposes may have the fifth band which indicates the failure rate. In the case of 6 band resistors, the 6th band shows the temperature coefficient in ppm/K.


What is the resistance of the following color-coded resistor?

Color code example

As the colors are Yellow, Violet, Orange, and Gold. The first two shows the two digits

Yellow = 4

Violet = 7

The next color is Orange showing the multiplier i.e.
Orange = $\times 10^{3}$

The fourth color is Gold which is the tolerance i.e.

Gold = ±5%

So, the final value of the resistor is

$R=47\times 10^{3} \pm 5\%$

$R=47k\Omega\pm 5\%\times 47k\Omega$

$R> 44.65k\Omega \quad and \quad R<49.35k\Omega$

The final value of the resistor is inside the range from 44.65k to 49.35kΩ. \(\)

Downsides of color coding:

Resistor color coding system has some drawbacks like in case of colorblind people. And recognition problems caused by overheating and dirt accumulation or differentiation between colors i.e. red, orange and brown.

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