Resistor color coding represents the rating of components by marking different colors on the components. The coding was introduced in the 1920s and then standardized in 1952 by the IEC. Use the Resistor Color Codes Calculator online to calculate the 4-band color.
Resistor Color Codes Calculator
Why Use Resistor Color Coding?
Originally, color coding was meant to be used for fixed resistors, capacitors, inductors, and diodes. Printing color bands was not easy or cheap on small components at that time. Advances in printing technology make it easier to print practically anything on these tiny electronic components, but the convention remains.
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Resistor Color Code Chart: Quick Reference
A resistor color code uses colored bands to represent its resistance value, multiplier, and tolerance. Each color corresponds to a specific numerical value.
| Color | Digit | Multiplier |
|---|---|---|
| Black | 0 | ×1 |
| Brown | 1 | ×10 |
| Red | 2 | ×100 |
| Orange | 3 | ×1,000 |
| Yellow | 4 | ×10,000 |
| Green | 5 | ×100,000 |
| Blue | 6 | ×1,000,000 |
| Violet | 7 | ×10,000,000 |
| Grey | 8 | ×100,000,000 |
| White | 9 | ×1,000,000,000 |
| Gold | — | ×0.1 |
| Silver | — | ×0.01 |
Resistor Color Code Tolerance Chart
The tolerance band indicates how much the actual resistance may vary from its nominal value.
| Color | Tolerance |
|---|---|
| Brown | ±1% |
| Red | ±2% |
| Green | ±0.5% |
| Blue | ±0.25% |
| Violet | ±0.1% |
| Grey | ±0.05% |
| Gold | ±5% |
| Silver | ±10% |
| No band | ±20% |
Tip: Gold and silver are used as multiplier and tolerance bands, but they are not significant-digit colors.
Resistor Color Code Chart
Each color has a value starting from 0 to 9. The coding also has room for tolerance in the rating. Tolerance is the percentage of error in the resistance value. The resistor color code chart is given below.
Resistor Value:
Colors are banded around the component, most commonly resistors. There are typically 4 color bands around the resistor. Starting from the left, the first two colors represent the first and second digits. The third one shows the multiplier using scientific notation (x10α). Finally, the fourth color band shows the tolerance in percentage.
Observing the diagram, you may notice the spacing between the last two color bands is different, which is on the right side of the resistor.
Resistors manufactured for 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.
How to Calculate Resistor Color Code (4-Band, 5-Band & 6-Band)
To calculate a resistor’s resistance value, read its colored bands from left to right. The number of bands determines how many significant digits are used in the calculation.
1. How to Calculate a 4-Band Resistor
A 4-band resistor uses the following arrangement:
- First band: First significant digit
- Second band: Second significant digit
- Third band: Multiplier
- Fourth band: Tolerance
The formula is:
Resistance = (First Digit × 10 + Second Digit) × Multiplier
Example: Calculate a 4.7 kΩ resistor
Suppose the resistor has these four colors:
- Yellow = 4
- Violet = 7
- Red = ×100
- Gold = ±5%
Calculation:
47 × 100 = 4,700 Ω
Therefore, the resistor value is 4.7 kΩ ±5%.
2. How to Calculate a 5-Band Resistor
A 5-band resistor provides greater precision because it uses three significant digits.
Its color arrangement is:
- First band: First significant digit
- Second band: Second significant digit
- Third band: Third significant digit
- Fourth band: Multiplier
- Fifth band: Tolerance
Example: Calculate a 4.7 kΩ resistor
Suppose the five bands are:
- Yellow = 4
- Violet = 7
- Black = 0
- Brown = ×10
- Brown = ±1%
Calculation:
470 × 10 = 4,700 Ω
Therefore, the resistor value is 4.7 kΩ ±1%.
3. How to Calculate a 6-Band Resistor
A 6-band resistor follows the same arrangement as a 5-band resistor, but it includes an additional temperature coefficient band.
The bands represent:
- First three bands: Significant digits
- Fourth band: Multiplier
- Fifth band: Tolerance
- Sixth band: Temperature coefficient
The temperature coefficient is measured in parts per million per Kelvin (ppm/K). It indicates how much the resistance changes with temperature.
For example, a 6-band resistor with Brown, Black, Black, Red, Brown, and Red bands has:
- Significant digits: 100
- Multiplier: ×100
- Resistance: 10,000 Ω
- Tolerance: ±1%
- Temperature coefficient: 50 ppm/K
Therefore, its nominal resistance is 10 kΩ ±1%, with a temperature coefficient of 50 ppm/K.
Important Tip for Reading Resistor Bands
Always identify the tolerance band before reading a resistor. The tolerance band is often separated slightly from the other bands and is commonly gold or silver on 4-band resistors.
Read the color bands from the opposite side, starting with the band closest to the edge of the resistor.
How to Check Resistor Color Code
To check a resistor’s color code, first identify the number of bands and their reading direction. Then use a resistor color code chart or calculator to determine its nominal resistance.
Follow these steps:
- Count the colored bands on the resistor.
- Identify the first band by locating the tolerance band, which is often separated from the other bands.
- Read the colors from left to right.
- Use the resistor color code chart to convert each color into its numerical value.
- Apply the multiplier to calculate the resistance.
- Check the tolerance band to determine the acceptable resistance variation.
For example, a resistor with Brown, Black, Red, and Gold bands has a resistance of:
10 × 100 = 1,000 Ω
Its nominal value is 1 kΩ ±5%.
You can also use the resistor color code calculator above to verify your result without performing the calculation manually.
If the resistor is installed in a circuit, use a multimeter to measure its actual resistance. For accurate measurements, disconnect at least one resistor lead from the circuit to avoid interference from parallel components.
Downsides of Resistor Color Code
The resistor color-coding system has some drawbacks, such as for colorblind people. And recognition problems caused by overheating and dirt accumulation, or difficulty differentiating between colors, i.e., red, orange, and brown.
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FAQs:
What Is the 330-Ohm Resistor Color Code for 4-Band and 5-Band Resistors?
For a 4-band 330-ohm resistor, the color code is Orange, Orange, Brown, and Gold. The first two bands represent 33, while Brown represents a multiplier of ×10. Gold indicates ±5% tolerance.
For a 5-band 330-ohm resistor, the color code can be Orange, Orange, Black, Black, and Brown. The first three bands represent 330, Black is the ×1 multiplier, and Brown indicates ±1% tolerance.
What is a 100-ohm resistor color code?
The color code for a 100-ohm resistor is brown, black, and brown.
What is the 1k resistor color code?
The color code for a 1k-ohm resistor is brown, black, and red.
What is the 2k resistor color code?
The color code for a 2k-ohm resistor is red, black, and red.
What is the 100k resistor color code?
The color code for a 100k-ohm resistor is brown, black, and yellow.
What is the 200k resistor color code?
The color code for a 200k-ohm resistor is red, black, and yellow.