How to Use the Resistor Color Code Calculator

Our resistor calculator is a versatile tool for both beginners and experienced electronics enthusiasts. Here's how to use it:

1. Color Code to Resistance Value

Select the number of bands (4, 5, or 6) on your resistor
Click on each colored band to select the appropriate color
The calculator will instantly display the resistance value, tolerance, and (for 6-band) temperature coefficient

2. Resistance Value to Color Code

Enter your desired resistance value and select the unit (Ω, kΩ, or MΩ)
Choose the tolerance percentage
For 6-band resistors, select the temperature coefficient
Click "Show Color Code" to see the band colors

Understanding Resistor Color Codes

Resistors use colored bands to indicate their resistance value, tolerance, and sometimes temperature coefficient. The color code system is standardized internationally:

Color	Digit Value	Multiplier	Tolerance	Temp. Coefficient
Black	0	10⁰	-	250 ppm/°C
Brown	1	10¹	±1%	100 ppm/°C
Red	2	10²	±2%	50 ppm/°C
Orange	3	10³	±3%	15 ppm/°C
Yellow	4	10⁴	±4%	25 ppm/°C
Green	5	10⁵	±0.5%	20 ppm/°C
Blue	6	10⁶	±0.25%	10 ppm/°C
Violet	7	10⁷	±0.1%	5 ppm/°C
Gray	8	10⁸	±0.05%	-
White	9	10⁹	-	-
Gold	-	10^-1	±5%	-
Silver	-	10^-2	±10%	-

Frequently Asked Questions

What is a resistor?

A resistor is a passive electrical component that limits or regulates the flow of electrical current in a circuit. Resistors are used to reduce current flow, adjust signal levels, divide voltages, and terminate transmission lines, among other uses.

Why do resistors have color codes?

Color coding provides a quick and reliable way to identify resistor values, especially when printed text would be too small to read. The color code system is standardized internationally, making it universally understandable.

What's the difference between 4, 5, and 6 band resistors?

4-band: 2 significant digits, multiplier, tolerance
5-band: 3 significant digits, multiplier, tolerance
6-band: 3 significant digits, multiplier, tolerance, temperature coefficient

How accurate are resistor values?

The accuracy depends on the tolerance indicated by the resistor's color code. For example, a 100Ω resistor with ±5% tolerance can actually measure between 95Ω and 105Ω.