



Electronics Resistor Color Code Calculator
Use this tool to determine values for resistors by colorcode, or you can do it the old fashioned way  here's how the calculation is done:
Color coding on resistors is simple. Each resistor has a value, and that value is expressed as a number. This number represents the amount of resistence, or Ohms. Each color has a specific number assigned to it: Brown = 1, Red = 2, etc. The first band represents the first half of the number (ex: the first half of "10" is "1"), the second band represents the second half of the number (ex: the second half of "10" is "0"), and the third band represents what you multiply that number by. Example:
Band 1 = Red = 2
Band 2 = Black = 0
Band 3 = Orange = 1000
Now, simply combine the values from bands 1 & 2, multiply the result (20) by band 3 (1000). Result: 20,000 Ohms (more commonly expressed as 20K  the "K" stands for "KiloOhms")
The fourth band represents the tolerance  uinless a specific tolerance is expressly stated in a schematic, you can most likely ignore this band (especially in low voltage electronics).
That's all there is to it. Here's a full description of the number values for each color, separated by bands:
Band 1
Black = 0
Brown = 1
Red = 2
Orange = 3
Yellow = 4
Green = 5
Blue = 6
Purple = 7
Gray = 8
White = 9

Band 2
Black = 0
Brown = 1
Red = 2
Orange = 3
Yellow = 4
Green = 5
Blue = 6
Purple = 7
Gray = 8
White = 9

Band 3
Black = 1
Brown = 10
Red = 100
Orange = 1,000
Yellow = 10,000
Green = 100,000
Blue = 1,000,000
Purple = 10,000,000
Gray = 100,000,000
White = 1,000,000,000

Band 4
Gold = +/ 5%
Silver = +/ 10%
None = +/ 20%

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