How To Read Resistor Color Code: A Comprehensive Guide

Tutorial 3

Till now we have learned how resistors work and also about different types of resistors that are extensively used in electronic circuits.  Understanding how to read resistor color codes is extremely important while working on electronics projects or debugging electronics circuits.

Practically speaking, resistors come in various shapes and sizes. However, in most cases, leaded resistors rated at one watt or sometimes two watts have color bands. These color bands are used to indicate their resistance value, tolerance, and sometimes even the temperature coefficient. The most common type of resistor has four color bands, but five- and six-band resistors are also extensively used in electronic circuits.

This guide will give you a quick and accurate method to read different resistors understand the concept behind the color band and understand those resistors values.

Why Resistor Color Code Matters?

Resistors are cylindrical and relatively small components. Due to their shape and size, it is difficult for most manufacturers to directly print the resistance value on the component. Additionally, colors are more durable than text and less prone to wear. A series of color bands can be used not only to indicate the resistance value but also to convey other important information.

Considering all these advantages and the convenience provided by color bands, the resistor color code is widely adopted. This color code was developed in 1920 by the Radio Manufacturers Association. These color bands can be used to identify a resistor’s resistance, tolerance, and sometimes even the temperature coefficient. In a typical four-band resistor, the first two bands indicate the resistance value, the third band serves as the multiplier, and the final band indicates the tolerance in percentage.

How to identify which end of the resistor to start reading from?

Reading resistor values using the color code can sometimes be confusing, as the color bands are spread across the entire body of the resistor. To avoid such mistakes, follow these guidelines:

• Start from the End Closest to the Bands
  Always begin reading from the end where the color bands are closest to the edge. If you carefully observe a resistor, you will notice that the color bands are marked so that one starting point is closer to the edge than the other. Start reading from the bands that are closest to the edge.
• Tolerance Band
  The tolerance band is often gold or silver in color. This band is usually placed slightly farther away from the other color bands. In most resistors, this is the last band.
• Temperature Coefficient Band
  In five- and six-band resistors, in addition to the tolerance band, there is another band representing the temperature coefficient. This band indicates how much the resistance changes with temperature variations.

How to Read Resistor Color Code in Easy Steps

Reading the resistor color code involves understanding what each color band represents and the information they convey. Resistors can have 4, 5, or 6 color bands, and each of these bands represents significant information.

The figure below shows the layout of a typical 6-band resistor. This same architecture is shared with five-band and four-band resistors as well. In a five-band resistor, the first three bands represent the digits, the fourth represents the multiplier, and the last band indicates the tolerance. In the case of a four-band resistor, the first two bands represent the digits, the third band represents the multiplier, and the fourth band indicates the tolerance.

If observed carefully the gap between the multiplier and tolerance specifies the left and right side of the resistor, which is a key point to notice.

How to read Resistor Color Code(4 Band) in 3 Easy Steps

In a 4-band resistor, the first two digits signify the value, the third digit represents the multiplier, and the final color band indicates its tolerance. Let’s first look at the 4-band resistor diagram along with the color code and then try to identify its value using a few examples.

Step 1: Identify the Starting Point

If we observe carefully, we can see that the green color band is much closer to the body of the resistor. This confirms that this is the starting point of the resistor color bands.

Step 2: First and Second Band Value

The first two colors in a four-band resistor represent its value. Here, if we observe carefully, the first two bands are green and blue. According to the color code chart, the value for green is 5, and the value for blue is 6.

Step 3: Multiplier Band

This color band represents the power of ten by which the first two digits should be multiplied. In our case, the multiplier band is red, and its corresponding multiplier value is 10².

Step 3: Tolerance Band

The final band indicates the tolerance value. This is measured in percentage and indicates how much the resistance can deviate from the actual calculated value. In our case, the tolerance band is silver, and its corresponding value is ±10%.

Now if we consider all these parameters and re-write in an appropriate order way.

Band Color in order	Green	Blue	Red	Silver
Digit Representation	5	6	102(Third band is multiplier)	±10%
Value	= 56×102±10% Ω = 5.6K Ω±10%

• Resistance Value : 5600 ohms(5.6K Ω)
  • This is the nominal resistance value.
• Tolerance: ±10%
  • This value signifies the actual resistance of the resistor can vary by ±10% from the nominal resistance value.
    • Minimum: 5600 × 0.90 = 5040 Ω
    • Maximum: 5600 × 1.10 = 6160 Ω

This value represents this resistor value is 5600 ohm and its tolerance represents it can vary within 10%. Practically speaking, its value can be somewhere between 5040 Ω -6160 Ω.

How to read Resistor Color Code(5 Band) in 3 Easy Steps

In a 5-band resistor, the first three digits signify the value, the fourth digit represents the multiplier, and the final color band indicates the tolerance. Let’s first look at the 5-band resistor diagram along with the color code and then try to identify its value using a few examples.

Step 1: Identify the Starting Point

If we observe carefully, we can see that the green color band is much closer to the body of the resistor. This confirms that this is the starting point of the resistor color bands.

Step 2: First, Second, and Third Band Value

The first three colors in a five-band resistor represent its value. Here, if we observe carefully, the first three bands are green, blue, and black. According to the color code chart, the value for green is 5, blue is 6 and green is 0.

Step 3: Multiplier Band

This color band represents the power of ten by which the first two digits should be multiplied. In our case, the multiplier band is red, and its corresponding multiplier value is 10².

Step 3: Tolerance Band

The final band indicates the tolerance value. This is measured in percentage and indicates how much the resistance can deviate from the actual calculated value. In our case, the tolerance band is silver, and its corresponding value is ±5%.

Now if we consider all these parameters and re-write in an appropriate order way.

Band Color in order	Green	Blue	Black	Red	Gold
Digit Representation	5	6	0	102(Third band is multiplier)	±5%
Value		= 56000±5% Ω = 56K Ω ±5%

• Resistance Value: 56000 ohms (56K Ω)
  • This is the nominal resistance value.
• Tolerance: ±5%
  • This value signifies the actual resistance of the resistor can vary by ±10% from the nominal resistance value.
    • Minimum: 56000 × 0.95 = 53,200 Ω
    • Maximum: 56000 × 1.05 = 58,800 Ω

This value represents this resistor value is 56000 ohm or 56K Ω and its tolerance represents it can vary within 5%. Practically speaking, its value can be somewhere between 53.2K Ω -58.8 K Ω

How to read Resistor Color Code(6 Band) in 3 Easy Steps

In a 6-band resistor, the first three digits signify the value, the fourth digit represents the multiplier, the fifth indicates the tolerance, and the final color band represents the temperature coefficient. Let’s first look at the 6-band resistor diagram along with the color code and then try to identify its value using a few examples.

Step 1: Identify the Starting Point

If we observe carefully, we can see that the green color band is much closer to the body of the resistor. This confirms that this is the starting point of the resistor color bands.

Step 2: First, Second, and Third Band Value

The first three colors in a five-band resistor represent its value. Here, if we observe carefully, the first three bands are yellow, blue, and black. According to the color code chart, the value for yellow is 4, the value for blue is 6, and the value for black is 0.

Step 3: Multiplier Band

This color band represents the power of ten by which the first three digits should be multiplied. In our case, the multiplier band is red, and its corresponding multiplier value is 10².

Step 3: Tolerance Band

The fifth band indicates the tolerance value. This is measured in percentage and shows how much the resistance can deviate from the actual calculated value. In our case, the tolerance band is gold, and its corresponding value is ±5%.

Now if we consider all these parameters and re-write in the appropriate order way.

Band Color in order	Yellow	Blue	Black	Red	Silver
Digit Representation	4	6	0	102(Third band is multiplier)	±10%
Value		= 46000±10% Ω = 46K Ω ±10%

• Resistance Value : 46000 ohms(46KΩ)
  • This is the nominal resistance value.
• Tolerance: ±5%
  • This value signifies the actual resistance of the resistor can vary by ±10% from the nominal resistance value.
    • Minimum: 46000 × 0.90 = 41,400 Ω
    • Maximum: 46000 × 1.10 =50,600 Ω

This value represents this resistor value is 46000 ohm or 46K Ω  and its tolerance represents it can vary within 10%. Practically speaking, its value can be somewhere between 41.4K Ω -50.6 K Ω

• Temperature Coefficient: 10ppm/K
  • This implies for every degree rise in temperature its resistance value changes by 10 parts per million.
  • For example, if the temperature changes by 10⁰ then, if we use the formula
  • ΔR = Resistance × Temp Coefficient × ΔT
  • $\Delta \mathrm{R}=46000 \times \frac{10}{1,000,000} \times 10=4.6 \Omega$

This implies for every 10⁰ K change; the resistance value will increase by 4.6

However, if we see the last band its color is Blue, from the table we get the value of 10 ppm/K. This value implies for every 1-degree change in temperature, the resistance value changes by 10 parts per million.

Example 1: 1K ohm Resistor Color Code

Let’s see the 1K ohm resistor color code along with the chart. From the chart we get,

• First Band (Digit 1 = 1): Brown
• Second Band (Digit 2 = 0): Black
• Third Band (Multiplier = 10²): Red
• Fourth Band (Tolerance = ±5%): Gold

Final Color Code for a 1kΩ Resistor:

• Brown – Black – Red – Gold

Explanation of the Bands:

Now, the equivalent value = 10×10²±5%

 = 1000Ω±5%

 = 1K Ω ±5%

Thus, a resistor with the color bands Brown, Black, Red, and Gold has a value of 1kΩ with a tolerance of ±5%.

Example 2: 10 K resistor color code

Let’s see the 10K ohm resistor color code along with the chart. From the chart we get,

• First Band (Digit 1 = 1): Brown
• Second Band (Digit 2 = 0): Black
• Third Band (Multiplier = 10³): ORANGE
• Fourth Band (Tolerance = ±10%): Silver

Final Color Code for a 10kΩ Resistor:

• Brown – Black – Orange – Silver

Explanation of the Bands:

Now, the equivalent value = 10×10³±10%

 = 10000Ω±10%

 =  10K Ω ±10%

Thus, a resistor with the color bands Brown, Black, Orange, Silver has a value of 1kΩ with a tolerance of ±10%.

Example 3: 100-ohm resistor color code

Let’s see the 100-ohm resistor color code along with the chart. From the chart we get,

• First Band (Digit 1 = 1): Brown
• Second Band (Digit 2 = 0): Black
• Third Band (Multiplier = 10): Brown
• Fourth Band (Tolerance = ±5%): Gold

Final Color Code for a 100Ω Resistor:

• Brown – Black – Brown – Gold

Explanation of the Bands:

Now, the equivalent value = 10×10±5%

 = 100Ω±5%

 =  100Ω ±5%

Thus, a resistor with the color bands Brown, Black, Brown, Gold has a value of 100Ω with a tolerance of ±5%.

Example 4: 220-ohm resistor color code

Let’s see 220-ohm resistor color code along with the chart. From the chart we get,

• First Band (Digit 1 = 2): Red
• Second Band (Digit 2 = 2): Red
• Third Band (Multiplier = 10): Brown
• Fourth Band (Tolerance = ±5%): Gold

Final Color Code for a 220Ω Resistor:

• Red – Red – Brown – Gold

Explanation of the Bands:

Now, the equivalent value = 22×10±5%

 = 220Ω±5%

 = 220Ω ±5%

Thus, a resistor with the color bands Red, Red, Brown, Gold has a value of 220Ω with a tolerance of ±5%.

Example 5: 330-ohm resistor color code

Example 5: 330-ohm resistor color code

• First Band (Digit 1 = 3): Orange
• Second Band (Digit 2 = 3): Orange
• Third Band (Multiplier = 10): Brown
• Fourth Band (Tolerance = ±10%): Silver

Final Color Code for a 330Ω Resistor:

• Orange – Orange – Brown -Silver

Explanation of the Bands:

Now, the equivalent value = 33×10±10%

 = 330Ω±10%

 = 330Ω ±10%

Thus, a resistor with the color bands Orange, Orange, Brown, Silver has a value of 330Ω with a tolerance of ±10%.

Common Mistakes that can happen while reading the Resistor Color Codes

• Always pay special attention when identifying the starting point. The color band closest to the edge is the starting point.
• Ensure you correctly identify the multiplier color band; sometimes, blue or violet can be confusing similarly, with yellow or orange. Double-check to make sure you have the right color.
• Count the number of bands to see if they are 4, 5, or 6. Many people mistakenly assume resistors only have 4 bands and overlook the multiplier and tolerance values.
• Pay attention to the tolerance value if the resistance is critical. It’s a good idea to choose resistors with tight tolerance bands if the value is extremely important.
• It’s advisable to note the temperature coefficient color band in the case of 6-band resistors.
• If the resistor color bands are unclear, it’s always a good idea to check the value with a multimeter to ensure accuracy.

Resistor Color Code Calculators

There are many resistor color code calculators available in both online and offline versions. Understanding the resistance value, tolerance, and temperature coefficient is very important for both beginners and professionals.

So far, we have covered the fundamental concepts of the resistor color code and learned about a few resistors along with examples. To simplify the process, we have also developed a simple resistor color code calculator.

How to Use:

This color code calculator is designed for 3, 4, 5, and 6-band resistors. Users can select the number of bands, and based on the input, the calculator will provide the appropriate resistance value, as well as the tolerance and temperature coefficient in the case of 6-band resistors.

Resistor Code Calculator

Conclusion

Now that you understand how to read resistor color codes, you can confidently tackle your electronics projects! Remember to reference this guide whenever you encounter resistors in your work. Happy tinkering!