Bands → Value

Resistance
Tolerance range

Value → Bands

How Resistor Color Codes Work

Most resistors use colored bands instead of printed numbers to show their value. On a standard 4-band resistor, the first two bands are significant digits, the third is a multiplier (how many zeros to add), and the fourth is the tolerance. 5-band resistors add a third digit for extra precision. Read the full breakdown in What Is a Resistor?

Want to size a resistor for an LED instead? Try the LED Resistor Calculator, or check the underlying formula in our Ohm's Law tutorial.