Resistor Colour Codes

The humble resistor is a key component of many renewable energy systems. They are designed to resist electricity and can therefore be used to supply the correct voltage or a suitably limited current to the various components in an electric circuit.

Because resistors are so small – too small to print numerical resistance values on – they are instead marked with four, five, or (less commonly) six coloured bands. Each colour represents a different number and so the value (in Ohms) of the resistor can easily be calculated.

Resistor Colour Code Chart

Resistor colour code chart

The last coloured band is usually used to indicate the tolerance – a measure of how accurate the stated resistance is, i.e. 1%, 2%, 5%, or 10%. In the case of six band resistors, is used to show the temperature coefficient – a measure of how much the resistance of a resistor is changed by changes in temperature.

Remembering the Resistor Colour Code Values

There are many mnemonic phrases to help you to remember the order of the colours:
Black Brown Red Orange Yellow Green Blue Violet Gray White
…which correspond to the values 0-9. For example:
Bad Beer Rots Our Young Guts But Vodka Goes Well.