Resistor Colour Code - Colour Chart, FAQs

Resistor Colour Code - Colour Chart, FAQs

Vishal kumarUpdated on 02 Jul 2025, 04:45 PM IST

The resistor color code is a system that is used to find out the value of resistance and tolerance of any resistor. This method uses a table that includes color bands with their respective values. In this article, we are going to learn about resistor color codes, resistance bands, resistance values, resistance band color codes, and resistor color coding formulas, and we will examine the color code chart.

This Story also Contains

  1. Resistor color code
  2. Resistance color code chart
  3. Reading a resistor color code
Resistor Colour Code - Colour Chart, FAQs
Resistor Colour Code

Resistor color code

In the electrical experiments, resistances starting from about 0.1 Ω to 1000 Ω are widely used. These types of resistances are generally made of copper or any other conducting metal or alloy. Usually in electronics goods, resistances are less than 1000 ohms. Nowadays, high-resistance graphite and gas carbon are used widely. These resistors are known as carbon resistors. The allotropes of carbon are a thousand times greater than metal. Carbon is very effective as an element of high resistance. The carbon resistors are cheaper than metal resistors.

Color code of carbon resistor

Color code of a carbon resistor

A cylindrical shell of a bad conductor is used to make a carbon resistor. The value of resistance can be determined by calculating the color codes drawn on the resistor. Two conducting metal wires are taken out from either side of the shell along its axis, through which the resistor is connected to the external circuit. The fourth color is drawn apart from the three consecutive colors. From the above diagram, we can see that the yellow color is apart from the two red and brown colors. From the colors of the resistor, we can calculate the resistance of the resistor.

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Resistance color code chart

Resistance color code charts or resistor color code calculators are used to calculate the resistance and tolerance values of resistors. There are 10 signal digits from 0 to 9, which correspond to 10 colors.

ColorDigitsMultiplierTolerance
Black0$10^0$
-
Brown1$10^1$± 1%
Red2$10^2$
± 2%
Orange3$10^3$
-
Yellow4$10^4$
-
Green5$10^5$
-
Blue6$10^6$
-
Violet7$10^7$
-
Grey8$10^8$
-
White9$10^9$
-
Gold-$10^{-1}$
±5%
Silver-$10^{-2}$
±10%
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As shown in the table, different colors represent different values in the resistor color code. The gold color code is the multiplier to the resistance value. The black color code is 0, the brown color code is 1, the red color code is 2, the orange color code is 3, the yellow color code is 4, the green color code is 5, and so on. It is the resistor color code calculator.

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Reading a resistor color code


Reading of a resistor color code

According to the given diagram of the resistor

Red, blue, violet, gold

For red and blue, we will put the values of the digit; for violet, we will write the multiplier; and for gold, we will write the tolerance.

The red color code is 2

For the blue digit, it is 6.

For violet, the digit is 7, so the multiplier is $10^7$.

For gold, the tolerance is ±5%

So the resistance of the given resistor, red, blue, violet, and gold, will be (26×$10^7$) ±5% Ω

How to remember the sequence of the color code:

To remember the color code sequence of the color code given above, by the sentence given below,

B B ROY of Great Britain has a very Good Wife wearing a Gold and Silver necklace.

Tolerance:

Tolerance is the product of the value of the resistor and the tolerance band value.

Also check

NCERT Physics Notes:

Frequently Asked Questions (FAQs)

Q: How has the resistor color code system evolved over time?
A:
While the basic principle has remained the same, the system has expanded to include more precise tolerances, additional significant digits (5-band resistors), and even temperature coefficients (6-band resistors). This evolution reflects the increasing precision requirements in modern electronics.
Q: What's the relationship between the number of significant digits and the precision of a resistor?
A:
More significant digits (as in 5-band resistors) allow for more precise resistance values. This is useful in applications requiring tighter control over circuit characteristics.
Q: How do you read a resistor with a black background?
A:
For resistors with a black background, the color bands are typically painted in lighter colors for contrast. The reading process remains the same, but extra care may be needed to distinguish the bands.
Q: What's the purpose of the multiplier band in the resistor color code?
A:
The multiplier band allows for a wide range of resistance values to be represented compactly. It indicates how many zeros should be added to the significant digits, effectively acting as a power of 10.
Q: How do you determine if a resistor is within its specified tolerance?
A:
Measure the resistor's actual value using a multimeter and compare it to the nominal value indicated by the color code. If the measured value falls within the tolerance range, the resistor is within specification.
Q: What does a yellow band represent when it's the tolerance band?
A:
A yellow band as the tolerance band is uncommon but represents a tolerance of ±4% when used.
Q: How do surface mount resistors (SMD) differ in marking from through-hole resistors?
A:
Surface mount resistors typically use a numerical code instead of color bands due to their small size. This code usually consists of three numbers representing the resistance value.
Q: What does a gray band represent when it's the first band on a resistor?
A:
A gray band as the first band represents the digit 8.
Q: How do you handle a situation where a resistor's color code seems to indicate an non-standard value?
A:
If a color code seems to indicate a non-standard value, first double-check your reading. If it still seems unusual, measure the resistance with a multimeter. The resistor might be custom-made, damaged, or incorrectly marked.
Q: What's the significance of the order of magnitude in resistor values?
A:
The order of magnitude, determined by the multiplier band, helps in quickly assessing a resistor's role in a circuit. For example, resistors in the kΩ range are often used for different purposes than those in the MΩ range.