Resistor Color Code Calculator

Decode resistor color bands to find resistance value and tolerance

How Resistor Color Codes Work

Understanding Color Bands

Resistors use colored bands to indicate their resistance value and tolerance. Each color represents a specific number or multiplier. Reading from left to right, the bands tell you the resistance in ohms.

4-Band Resistors

Band 1 & 2: First and second significant digits
Band 3: Multiplier (number of zeros)
Band 4: Tolerance (accuracy)

5-Band Resistors

Band 1, 2 & 3: First, second, and third significant digits
Band 4: Multiplier (number of zeros)
Band 5: Tolerance (accuracy)

Color Values

Black = 0, Brown = 1, Red = 2, Orange = 3, Yellow = 4, Green = 5, Blue = 6, Violet = 7, Gray = 8, White = 9

Tolerance Ratings

Gold: ±5%
Silver: ±10%
Brown: ±1%
Red: ±2%
None: ±20%

Example Calculation

A resistor with bands: Brown, Black, Red, Gold
Brown = 1, Black = 0, Red = ×100, Gold = ±5%
Resistance = 10 × 100 = 1,000Ω or 1kΩ ±5%