Resistor color coding

Do you need to know the color coding of resistors to calculate its value? Here we show you what it is, how to calculate the value of a resistor and an online calculator through which you can select the color of each band and calculate its value without making calculations.

We leave you with the resistance calculator The four-band display, in which you simply select the color of each band and it will automatically show you its value and tolerance.

The color code of the resistors

For calculate the value of a resistor The first thing we have to do is to identify the number of bands it has. There can be 4, 5 or 6 bands, so depending on the type of resistance, each band will mean one thing, so here is a summary for you to understand the function of each one:

 4-band resistor5-band resistor6-band resistor
1st band1st significant digit1st significant digit1st significant digit
2nd band2nd significant digit2nd significant digit2nd significant digit
3rd bandmultiplier3rd significant digit3rd significant digit
4th bandtolerancemultipliermultiplier
5th band-tolerancetolerance
6th band--temperature coefficient

Now that you know what each band is used for, let's take a look at the color coding of the resistors.

Color 1st Band 2nd Band 3rd Band Multiplier Tolerance Coef. temp.
Black 0 0 0
Brown 1 1 1 10Ω ±1% 100 ppm/ºC
Red 2 2 2 100Ω ±2% 50 ppm/ºC
Orange 3 3 3 1000Ω 15 ppm/ºC
Yellow 4 4 4 10000Ω 25 ppm/ºC
Green 5 5 5 10000Ω ±0.5%
Blue 6 6 6 1000000Ω ±0.25% 10 ppm/ºC
Violet 7 7 7 10000000Ω ±0.10% 5 ppm/ºC
Gray 8 8 8 100000000Ω ±0.05%
White 9 9 9 1000000000Ω
Gold 0,1Ω ±5%
Silver 0,01Ω ±10%

If you want to know a little more about what each of the bands means, let's take a look at each of them in a little more detail below:

Significant digits

Each color represents a number if it is in the first and second band in the case of 4-band resistors. If the resistor is a 5- or 6-band resistor, the first three bands are significant digits.

Multiplier

The multiplier can be found in:

  • The third band if it is a 4-band resistor.
  • On the fourth band if we have a 5 or 6 band resistor

If you look, the number of zeros of each color is equal to the number we have seen in the columns of significant digits. That is, if the white color corresponds to 9 as a significant number, it will multiply by x1000000000 (there are 9 zeros) in its work as a multiplier. This happens in the same way with the rest of the colors.

Tolerance

Tolerance in a resistance gives us a margin of error that can be above or below the total value. of resistance.

The tolerance value is in the fourth or fifth band and its value is also determined according to the color code of the resistor.

For example, if we have a 5KΩ resistor with a tolerance of ±5%, that means that its actual value can range from 4,750 Ω to 5,250 Ω.

Logically, the smaller the tolerance, the more likely it is that the resistance value will be what it should theoretically be.

How to calculate the value of a resistor

For calculating the ohms value of a resistor we simply need to do the following steps:

  1. Identify significant numbers and group them in order.
  2. Multiply the significant numbers by the value of the multiplier
  3. Add to the result other parameters such as tolerance or temperature coefficient.

The procedure is similar for any resistanceeither 4, 5 or 6 bands.

For example, if we have a four band resistor with the colors green, blue, red and gold, let's calculate its value in ohms:

 1st Band2nd Band3rd Band4th Band
ColorGreenBlueRedGold
Value56x100±5%

Therefore:

56 x 100 = 5600Ω with ±5% = 5.6 KΩ ±5%

Here is a collection of solved exercises for you to practice with different values.

4-band resistance exercises

4-band resistor

Calculate the value of the following four-band resistors based on the colors below:

  • Green, blue, red, gold: 5.6 KΩ and ±5%
  • Red, yellow, orange, gold: 24 KΩ and ±5%
  • Blue, gray, yellow, silver: 680 KΩ and ±10%

5-band resistance exercises

5-band resistor

Obtain how much the following five-band resistors are worth in ohms:

  • Red, yellow, orange, black, brown: 243 ohms and ± 1%

Examples of 6-band resistors

6-band resistors

Find the value of the following six-band resistors, including their tolerance and temperature coefficient:

  • Red, red, brown, brown, brown, brown. red: 2.21 KΩ, ±1% and 50ppm/ºC.
  • White, black, white, white, brown, red, red: 9.09 KΩ, ±2% and 50ppm/°C

Frequently Asked Questions

Here we will answer some of the most common questions that arise when it comes to the following questions calculate the value or work with the color coding of resistors:

Resistance has only 3 bands

If you come across a resistor that has 3 bands, you can calculate its value as if it were a 4-band resistor (digit, digit and multiplier).

For tolerance we will put a 20%.

Which band is first in a resistance?

There are a number of rules for knowing which is the first band in a resistance:

  1. Some resistors have groupings of several bands close together and then one or two more separate ones. Put the band grouping to your left and calculate the resistance value from left to right.
  2. Resistors that have a tolerance of a 5% (gold) or a 10% (silver), it is very easy since in these cases we already know that that band will be the last. Therefore, put the gold or silver band on the right and calculate the resistance value from left to right.
  3. As mentioned in the previous point, the first band can never be silver or gold. Nor is it usual to find a black first band. For

What happens if I calculate the resistance value backwards?

If you have not been able to see which is the first band of the resistor and you have calculated the value of the resistor, ehe result you will probably have obtained does not appear in the table of usual resistor values.

Yes the resistance you have calculated does not have a standard valueIf you have done it wrong, it is likely that you have done it wrong.

You can also use a multimeter to obtain the value of a resistor to check if the calculation you have made is correct or not.

Resistance calculator

Resistance calculator

Our resistance calculator allows you to calculate the value in ohms of four band resistors, i.e., the most common in school or even university work.

You must simply choose the color of each band from left to right and you will automatically get the value in ohms of the resistance, including the tolerance.

Doubts about how to calculate the value of a resistor from the color coding? Leave us a comment and we will help you!

23 thoughts on “Código de colores de resistencias”

    • Hello nasf,

      A 5-band resistor cannot have a black color in the tolerance band.

      If it's black, you're probably reading it backwards.

      Greetings!

    • Hello Rafael,

      Well, I'm afraid you're having to read it backwards since the last band cannot be black because it corresponds to the tolerance in the case of five band resistors.

      Greetings!

    • If the fifth band has no color (white is considered color), then it is a four-band resistor.

      If it really is a five-band resistor and has lost its color, the only way to calculate its resistance is to use a multimeter.

      Greetings!

  1. I have a resistor from a power card and it has 5 bands, brown, red, gray, gold and black.
    And I measure it xon the tester and it gives me .7 ohms be correct el.valor o debe ser segun su calxuladora de 1.8k

    Reply
    • Our calculator is only valid for 4-band resistors, so you must rely on the value of your tester.

      Greetings!

    • Hi Victor, you will surely find some on the internet. We don't have something like that yet but we will add it in the future.

      Greetings!

  2. Good morning

    I have an open resistor and the tester does not mark anything.
    I just don't know what the value might be since I have two golds in the middle.

    BLACK-GOLDEN-GOLDEN-GOLDEN-BLACK-RED

    Could you help me with the value, thank you.

    Reply
  3. Hello good afternoon, I have a question I ask 2 Ohm 2%, you can have 2 answers or more ? is it okay to say that it is black, red, black, red and also red black gold red. Are the two answers OK? I have this doubt, Thank you very much.

    Reply
    • Hello Jian,

      Resistors do not usually have the first band in black because its value is null, i.e., we would be talking about the first significant digit being null and, therefore, it could be considered as a 3-band resistor. If you are not limited in the number of bands of the resistor, the answers you have given are correct.

      Greetings!

  4. I have a 5 band resistor that is orange, brown, gold, gold, gold, black, no matter which side you read it from, you can't read it because it would have black at the beginning or at the end and two gold colors in the middle, so I don't know what value it is, could you help me? the tester doesn't mark it because it is open.

    Reply
    • Hi Jorge,

      We do not agree with the colors you give with what you say below that it does not matter from which side it is read because it is symmetrical. With the colors you have sent us, it is clear that the resistance is not symmetrical.

      If you repeat them correctly, we will help you.

  5. quisiera saber de q valor es una resistencia con los siguientes colores azul gris plateado dorado y de ultimo tiene rojo

    Reply

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