The resistor color code is used to indicate the value of through hole resistors below 1 Watt. Surface mount resistor markings are generally an alphanumeric code. On large power resistors and potentiometers the value is usually given explicitly. The codes are defined in IEC 60062.
Resistors are available mainly in two series of preferred values, E12 (12 values per decade) and E24 (24 values per decade). Carbon resistors with a tolerance 5% and less are available in the E12 series while metal film resistors with 2% and better tolerance are available in the E24 series.
Help to remember
Without a mnemonic: Black is darkest, brown is a dark shade of red, then the color spectrum ROY G. BIV, then grey as colour is lost, and white is brightest. Gold has a better value than silver.
How to read
The first band is closest to one end. If there is a gap between bands 3 and 4, band 4 is the tolerance. Gold or silver gives the tolerance and the tolerance is usually the last band. Pink for the tolerance band shows it's ±20%.
A resistor with a single black band is a zero-ohm resistor and can be replaced by a wire link.
With four band resistors the first two bands give the first two digits of the resistance, the third band the multiplier and the fourth gives the tolerance.
|Band 1 & 2||Band 3||Band 4|
With five band resistors, the first three bands give the first three digits of the resistance, the fourth band the multiplier, and the fifth band the tolerance. If there is a sixth band, it indicates the temperature coefficient.
|Band 1,2 & 3||Band 4||Band 5||Band 6|
|Color||Digit||Multiplier||Tolerance %±||Tempco (ppm/°C)|
Resistors with only three bands have a 20% tolerance.
|Band 1 & 2||Band 3|
- A Users Guide to Selecting Electronic Components by Gerald L Ginsberg, John Wiley & Sons Inc, 1981, ISBN 0-471-08308-9
- Passive Components: a user's guide by Ian Robertson Sinclair, Butterworth-Heinemann Ltd, 1991, ISBN 0-7506-0229-5