The fourth band is a TOLERANCE band. There are only two possible bands here: Silver (10%) and Gold (5%) if there is no band the resistor is 20% tolerance. EXAMPLE: A 1000 Ohm resistor with a 20% tolerance could be an 900 Ohm or 1100 Ohm value and still be within TOLERANCE. NOTE: Silver is most common in modern supply as we know it. The Resistor Color Code Calculator identifies the value and tolerance of a color coded resistor given its bands colors. Supports resistors with 3, 4, 5 and 6 bands. Color coded resistors Mnemonics are used to help memorize the electronic color codes of electronic components such as resistors. The first letter of the color code is matched by order of increasing magnitude. This resistor colour code calculator is designed to find the resistance and tolerance values of through-hole resistors. Resistor Colour Code Calculator Resistor Colour Code Chart. It appears you have JavaScript disabled within your browser. Functions on this.

What is a resistor?

Resistors are the passive components used in the electrical circuits to reduce the flow of electric current to certain level. The ability to restrict the flow of electric current is called resistance. The resistors with high resistance value will restricts large amount of electric current whereas the resistors with low resistance value will restricts only a small amount of electric current. The resistance of a resistor is measured in ohms.

What is a color code?

Generally, code refers to a representation of information in another form by using symbols, signals, and letters for the purposes of secrecy. Here, the signals or symbols act as codes. In the similar way, in resistors we use different colors as codes to specify the resistance (information) of the resistor. Here, the different colors coated on the resistor act as codes.

The color codes are also used to specify the tolerance and reliability of the resistor. We can also directly find the resistance value of a resistor by using ohmmeter.

The color codes are used not only in resistors but also in other electronic components such as capacitors and inductors.

Specifying the values or ratings of electronic components such resistors, capacitors, and inductors by using the color codes printed on them is called electronic color code system. The electronic color code system was developed in the early 1920s by the radio manufactures association, which is now part of Electronic Industries Alliance (EIA).

The color-coding is done only in the fixed resistors but not in variable resistors because the color coding technique shows only a fixed resistance value. The variable resistors have varying resistance. Hence, it is not possible to use the color coding technique in variable resistors.

Why color codes are used in resistors instead of directly printing the resistance value?

Printing the numbers on large electronic components is very easy, but it is very difficult to print the numbers or resistance values on tiny components. Hence, instead of directly printing the numbers, we print the color codes or color bands. However, by using the latest printing technology we can directly print the numbers on resistors.

The color coding technique has some drawbacks. For blind people, it is impossible to find the resistance of the resistor, because they cannot see the colors coated on the resistor.

Another drawback is recognizing the difference between two colors in an overheated resistor is very difficult. When the resistor is overheated, the colors on the resistor changes slightly. Therefore, it becomes impossible to recognize the difference between brown color and red color or brown color and orange color.

Representing the resistance of a resistor by using color bands

In a color coding technique, the resistors value is marked on the resistors body by using colors. The colors painted on the resistors body are called color bands. All the color bands painted on the resistor body are used to indicate the resistance value and tolerance. Each color on the resistors body represents a different number.

The color bands of resistors are basically of three types: 4 band resistor, 5 band resistor, and 6 band resistor. In order to find the resistance of a resistor, we need to decode the colors painted on the resistors body. The decoding changes based upon the number of color bands painted on the resistors body.

4 band color code resistor

A 4 band color code resistor has 3 color bands on left side and one color band on right side. The 3 color bands on left side are very close to each other and the 4^th color band on right side is separated from first 3 bands with some space.

The 3 color bands on the left side are grouped together to indicate the resistors resistance value and the 4^th color band on the right side indicates the tolerance of the resistor.

What is tolerance? 'Tolerance is the variation in the resistance of a resistor from its actual resistance. The resistors of high tolerance have high variation in the resistance. The resistors of low tolerance have low variation in the resistance. For example, a resistor that has a tolerance of 5% may vary 5% of its resistance from its actual resistance value. Similarly, a resistor that has a tolerance of 8% may vary 8% of its resistance from its actual resistance value. Tolerance of a resistor is normally specified in percentage.'

The 1^st color band on the resistor indicates the 1^st significant value or 1^st digit of the resistors resistance and the 2^nd color band indicates 2^nd significant value or 2^nd digit of the resistors resistance. The 3^rd color band is the decimal multiplier and the 4^th color band indicates the resistors tolerance.

The 1^st and 2^nd color bands together make up a 2 digit number and the 3^rd color band or multiplier is multiplied with this 2 digit number to obtain the resistance value of the resistor.

If the 4^th color band or tolerance band is left blank, it is considered as the 3 band resistor and the tolerance for the 3 band resistor is assumed to be 20%.

Resistors that are manufactured for military use may also include an extra band called 5^th band which indicates resistor failure rate.

Example:

If the colors on a 4 band resistor is in this order: brown, green, red and violet (as shown in figure). The values of color bands will be like this: Brown = 1, Green = 5, Red = 10² or 100, Violet = 0.10%.

In the color code table, brown has a value of 1 which is the 1^st digit and green has a value of 5 which is the second digit. The first and second color bands are grouped together to make up a two digit number 15. The 3^rd color band red has a value of 100. This value is multiplied with the two digit number I.e., 15x 100 = 1500 ohms. Violet specifies that the tolerance is 0.10%.

Therefore, the resistor color coded with brown-green-red-violet would have a resistance of 1500 ohms with a tolerance of ± 0.10%.

5 band color code resistor

A 5 band color code resistor has 4 color bands on left side and one color band on right side. The 4 color bands on left side are very close to each other and the 5^th color band on right side is separated from the first 4 bands with some space.

The 4 color bands on the left side are grouped together to represent the resistance value of a resistor and the 5^th color band on the right side indicates the tolerance of the resistor.

• The 1^st color band indicates the 1^st significant value or 1^st digit of the resistors value.
• The 2^nd color band indicates the 2^nd significant value or 2^nd digit of the resistor value.
• The 3^rd color band indicates the 3^rd significant value or 3^rd digit of the resistors value.
• The 4^th color band is the decimal multiplier.
• The 5^th color band indicates the resistors tolerance.

The 1^st, 2^nd and 3^rd color bands together make up a 3 digit number and the 4^th color band or multiplier is multiplied with this 3 digit number to obtain the resistance value of the resistor.

Example:

If the colors on a 5 band resistor is in this order: brown, green, red, blue and violet (as shown in figure). The values of color bands will be like this: Brown = 1, Green = 5, Red = 2, blue = 10⁶, Violet = 0.10%.

In the color code table, brown has a value of 1 which is the 1^st digit, green has a value of 5 which is the second digit and red has a value of 2 which is the 3^rd digit. The first, second and third color bands together make up a three digit number 152. The 4^th color band blue has a value of 10⁶. This value is multiplied with the three digit number 152 I.e., 152x 10⁶ = 152MΩ. Violet specifies that the tolerance is 0.10%.

Therefore, the resistor color coded with brown-green-red-blue-violet would have a resistance of 152MΩ with a tolerance of ± 0.10%.

6 band color code resistor

A 6 band color code resistor consists of 6 color bands. The 4 color bands on the left side are grouped together to represent the resistors resistance value. The 5^th color band on the right side represent the tolerance of the resistor and the 6^th color band represents the TCR (Temperature Co-efficient of Resistance).

• The 1^st color band indicates the 1^st significant value of the resistors value.
  
• The 2^nd color band indicates the 2^nd significant value of the resistors value.
• The 3^rd color band indicates the 3^rd significant value of the resistors value.
• The 4^th color band is the decimal multiplier.
• The 5^th color band indicates the resistors tolerance.
• The 6^th color band indicates the TCR (TemperatureCo-efficient of Resistance).

The 1^st, 2^nd, and 3^rd color bands together make up a 3 digit number and the fourth color band is multiplied with this 3 digit number to get the resistance value of the resistor.

Example:

If the colors on a 6 band resistor is in this order: green, brown, violet, black, gold and orange. The values of color bands will be like this: Green = 5, Brown = 1, Violet = 7, Black = 10⁰, Gold = 5%, Orange = 15ppm.

In the color code table, green has a value of 5 which is the 1^st digit, brown has a value of 1 which is the second digit and violet has a value of 7 which is the 3^rd digit. The first, second and third color bands together make up a three digit number 517. The 4^th color band black has a value of 10⁰. This value is multiplied with the three digit number 517 I.e., 517x 10⁰ = 517 ohms. Gold specifies that the tolerance is 5% and orange specifies that the TCR is 15ppm.

Therefore, the resistor color coded with green-brown-violet-black-gold-orange would have a resistance of 517 ohms with a tolerance of 5% and TCR (Temperature Co-efficient of Resistance) of 15ppm.

What is TCR? The rate at which the resistance of the resistor changes with change in temperature is called TCR (Temperature Co-efficient of Resistance).

How to read or decode resistor color codes

The placement of the color bands on the resistor is very important. Generally, the color bands placed closest to the lead or end of the resistor is considered as the first band. The next to the first band is second band and so on. Another way is the extra space between the two bands (3^rd and 4^th bands) also indicates the reading direction.

If you feel difficult to find the resistance of the resistor by using its color bands, you can directly find the resistance by using ohmmeter or multimeter.

How to remember color codes on the resistor?

If you find difficult to remember the color codes on the resistor, use these mnemonics to remember them easily. The bold letters represents color names.

Some mnemonics that are easy to remember include:

• B.B. ROY of Great Britain has a Very Good Watch made of Gold Silver
• Bye Bye Rosie Off You Go Birmingham Via Great Western
• Bye Bye Rosie Off You Go Bristol Via Great Western
• Better Buy Resistors Or Your Grid Bias Voltages Go West
  

Resistor Color Code Bands
& Other Component Identification

Resistor Color Code Identification

While these codes are most often associated with resistors, then can also apply to capacitors andother components.

The standard color coding method for resistors uses a different color to represent each number 0 to 9:black, brown, red, orange, yellow, green, blue, purple, gray, white. On a 4 band resistor, the first twobands represent the significant digits. On a 5 and 6 band, the first three bands are the significant digits.The next band represents the multiplier or 'decade'. As in the above 4 band example, the first two bandsare red and purple, representing 2 and 7. The third band is orange, representing 3 meaning 10³ or 1000.This gives a value of 27 * 1000, or 27000 Ohms.The gold and silver decade bands divide by a power of 10, allowing for values below 10 Ohms.The 5 and 6 band resistors work exactly the same as the 4 band resistor. They just add one more significant digit.The band after the decade is the tolerance. This tells how accurate the resistance compared to its specification.The 4 band resistor has a gold tolerance, or 5%, meaning that the true value of the resistor could be 5%more or less than 27000 Ohms, allowing values between 25650 to 28350 Ohms.The last band on a 6 band resistor is the temperature coefficient of the resistor, measured in PPM/C orparts per million per degree Centigrade. Brown (100 PPM/C) are the most popular, and will work for mostreasonable temperature conditions. The others are specially designed for temperature critical applications.

Alpha-Numeric Code Identification

Resistor Color Code Chart

With the sizes of resistors and other components shrinking or changing in shape, it is gettingdifficult to fit all of the color bands on a resistor. Therefore, a simpler alphanumeric coding systemis used. This method uses three numbers, sometimes followed by a single letter. The numbers representthe same as the first three bands on a 4 band resistor. On the above SIL network, the 4 and 7 are thesignificant digits and the 3 is the decade, giving 47 x 1000 or 47000 Ohms. The letter after the numbersis the tolerance. The different representations are: M=±20%, K=±10%, J=±5%, G=±2%, F=±1%.

Naming Convention

To simplify the writing of large resistor values, the abbreviations K and M are used for one thousandand one million. To keep the convention standard, R is used to represent 0. Because of problems in seeingthe decimal point in some printed texts, the 3 letters: K M or R are used in place of the decimal point.Thus, a 2,700 Ohm resistor is written 2K7 and a 6.8 Ohm resistor is written 6R8.

The E12 Range

These identify a range of resistors that are know as 'preferred values'. In the E12 range thereare 12 'preferred' or 'basic' resistor values, and all of the others are simply decades of these values:

1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8 and 8.2

The table below lists every resistor value of the E12 range of preferred values. You will noticethat there are 12 rows containing the basic resistor values, and the columns list the decadevalues thereof. This range most commonly covers standard carbon film resistors, which are notreadily available in values above 10 Megohms - 10M (10 Million Ohms)

1R0	10R	100R	1K0	10K	100K	1M0	10M
1R2	12R	120R	1K2	12K	120K	1M2	n/a
1R5	15R	150R	1K5	15K	150K	1M5	n/a
1R8	18R	180R	1K8	18K	180K	1M8	n/a
2R2	22R	220R	2K2	22K	220K	2M2	n/a
2R7	27R	270R	2K7	27K	270K	2M7	n/a
3R3	33R	330R	3K3	33K	330K	3M3	n/a
3R9	39R	390R	3K9	39K	390K	3M9	n/a
4R7	47R	470R	4K7	47K	470K	4M7	n/a
5R6	56R	560R	5K6	56K	56OK	5M6	n/a
6R8	68R	680R	6K8	68K	680K	6M8	n/a
8R2	82R	820R	8K2	82K	82OK	8M2	n/a

The E24 Range

Resistor Color Code

Resistor Color Code 2

The E24 range of preferred values includes all of the E12 values, plus a further 12 to enablethe selection of more precise resistances. In the E24 range the preferred values are:

1.0, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2.0, 2.2, 2.4, 2.7, 3.0, 3.3, 3.6, 3.9, 4.3, 4.7,5.1, 5.6, 6.2, 6.8, 7.5, 8.2 and 9.1

Resistor Color Code Mnemonic

The table below lists every resistor value of the E24 range of preferred values. You will noticethat there are 24 rows containing the basic resistor values and the columns to the right listthe decade values thereof. This range most commonly covers metal film resistors which are notreadily available in values above 1 Megohm - 1M0.

1R0	10R	100R	1K0	10K	100K	1M0
1R1	11R	110R	1K1	11K	110K	n/a
1R2	12R	120R	1K2	12K	120K	n/a
1R3	13R	130R	1K3	13K	130K	n/a
1R5	15R	150R	1K5	15K	150K	n/a
1R6	16R	160R	1K6	16K	160K	n/a
1R8	18R	180R	1K8	18K	180K	n/a
2R0	20R	200R	2K0	20K	200K	n/a
2R2	22R	220R	2K2	22K	220K	n/a
2R4	24R	240R	2K4	24K	240K	n/a
2R7	27R	270R	2K7	27K	270K	n/a
3R0	30R	300R	3K0	30K	300K	n/a
3R3	33R	330R	3K3	33K	330K	n/a
3R6	36R	360R	3K6	36K	360K	n/a
3R9	39R	390R	3K9	39K	390K	n/a
4R3	43R	430R	4K3	43K	430K	n/a
4R7	47R	470R	4K7	47K	470K	n/a
5R1	51R	510R	5K1	51K	510K	n/a
5R6	56R	560R	5K6	56K	56OK	n/a
6R2	62R	620R	6K2	62K	620K	n/a
6R8	68R	680R	6K8	68K	680K	n/a
7R5	75R	750R	7K5	75K	750K	n/a
8R2	82R	820R	8K2	82K	82OK	n/a
9R1	91R	910R	9K1	91K	910K	n/a

Resistor Color Code 5 Band

There are also E48 and E96 tables, which have even more values. Resistors in thesegroups are less common and tend to have a better tolerance rating.

Resistor Color Code Mnemonic

The table below shows the color codes for the E12 and E24 preferred values. Notice how the first twocolors in each row are the same, and the last color in each column is the same. Each column is a decade,and each row in that column is a different one of the E24 values.