The value of the resistor is marked on the body using colors. Every color is different number and you can remember these numbers or you can just use the table on next step. OR there are much resistor calculators that you can use. It's for the laziest people :D .  However it's your decision ,and I will show you all ways to calculate resistor value.


Here is the table with the colors and numbers. As you can see they are:
  • BLACK:     0
  • BROWN:   1
  • RED:           2
  • ORANGE:   3
  • YELLOW:   4
  • GREEN:       5
  • BLUE:          6
  • VIOLET:      7
  • GREY:          8
  • WHITE:        9
But this is not for all colors. From right to left the second color is multiplier. Digits from the first colors must be multiplied with the number of this color.
  • BLACK:     1
  • BROWN:   10
  • RED:           100
  • ORANGE:   1000
  • YELLOW:   10000
  • GREEN:       100000
  • BLUE:          1000000
  • GOLD:          0.1
  • SILVER:       0.01
And the last color: This is tolerance. Tolerance is the precision of the resistor and it is given as a percentage. For example a 390 resistor with a tolerance of ±10% will have a value within 10% of 390, between 390 - 39 = 351 and 390 + 39 = 429 (39 is 10% of 390).
  • BROWN:   1%
  • RED:           2%
  • GOLD:        5%
  • SILVER:     10%
  • NOTHING:  20%


Resistor color code calculator
If you are too lazy to think about colors and digits and mat ... this is for you :) :D


Exemple: If first color is RED ,second is RED ,third is BLACK and the last is SILVER it means:
RED - 2  --  RED - 2  --  YELLOW - x10000  --  SILVER - 10%          so...
2   2   0000 +/- 10% * 2 2 0000   so... :D
220000 +/- 22000
This is 220 000 Ohm or 220 kOhm
or 220 000 - 22 000 Ohm or 220 - 22 kOhm
or 220 000 + 22 000 Ohm or 220 + 22 kOhm

Hope you got it :)


Now some exercises :)
Try to calculate resistors' values from third and forth picture.
Answers are below.


The first one is        :  11000  =   11k ohms
The second one is :  1000    =    1k ohms
The both are with gold color for the tolerance ,it means 5%.

It's your answer? I hope so :)
<p>This was so helpful. I had a booklet that tried to explain it, but chose the most difficult way to explain something that it turns out is really easy! Although, as pointed out already, your answers are switched. Made me double-check my answers though, so maybe not a bad thing!</p>
<p>You mention that you read from left to right - but if you flip the resistor over, these directions are reveresed. How do I know which side is 'left' on a resistor?</p>
<p>It's the closest band to end of the resistor.</p>
<p>Hey, I can answer that question for you, if you haven't found your answer quite yet. The tolerance band should be on the far right when you are looking at it. It could be Gold(5%) or Silver(10%). This means it should be xcolour, ycolour, zcolour and then your gold or silver tolerance band when you look at it. This way it is consistent and is facing the right way in order to measure the resistance when going to calculate it. As for putting your resistor in a circuit, well resistors are not polarized , therefore you can put them in any way. Good luck!</p>
<p>Hi, I think the answers are switched</p>
<p>The answers are switched. Using the tool provided, the first resistor is actually the second answer.</p>
<p>how will be if you have given colour code indigo, red, red and gold</p>
<p>how will be if you have given colour code indigo, red, red and gold</p>
<p>Thank you for information . you help me :-)</p>
<p>Are you scared</p>
<p>In your example you give the color code -(red, red, black, silver)- </p><p>&quot;it means: RED = 2, RED = 2, YELLOW=(x10000), SILVER = 10%&quot;</p><p>Shouldn&rsquo;t it be: red = 2, red = 2, BLACK = (x1), silver = +/-10%</p><p> 22*1 = 22+/-10% </p>
Ops .. :dd My fault .. ;d
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You could always connect a resistor up to your multimeter set on the ohms scale too.
Unless it is soldered into a circuit. Then you would have to unsolder one end to isolate it from the rest of the circuit.

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