Resistor Color Code Calculator

Resistors are measured in ohms. Color "bands" are used to specify each band. There are three bands and sometimes four. The fourth band is the tolerance (Gold or Silver) if there is no band the tolerance is 20%.

The first three bands are colored:
Black = 0   Brown = 1  Red = 2  Orange = 3  Yellow = 4
Green = 5   Blue = 6   Violet = 7   Gray = 8   White = 9
The fourth band (if any) is colored:
Gold = 5%,   Silver = 10% (NONE = 20%)
To use this calculator simply select the color for each band from the drop down menus. Click "display value" for the result. To re-calculate, simply re-select any one of the drop down color bands, and continue...

The color bands one and two are NUMBERS BLACK = 0, BROWN = 1 etc. (see colors above). EXAMPLE: BROWN, BLACK would be 10, while BLACK, BROWN is 1 (drop the 0). The third band is a (X) multiplier of the first 2 bands; Black = 1, Brown = 10,  Red = 100, Orange = 10K, Yellow = 100K, Green = 1M, Blue = 10M. EXAMPLE: Brown, Black, Blue = 10M Ohms. NOTE: The Black band is not used above 9 Ohms, Brown is the first band for all resistors with a value for 10 - 100 - 1000, 10,000  etc. EXAMPLE: Brown, Black, Red = 1000 Ohms not Black, Brown, Orange as this calculator will display as 1000 Ohms.

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. NOTE: Some Japanese resistors have shown a band of Black (20%) or a band of White (2%). However these are rare and this calculator does not share the values.

I found this code on an old web site and would like to acknowledge the author.