Resistor Color Code Calculator

Decode resistor values from color bands or find the color code for a resistance value.

Color Code Guide:

Black: 0
Brown: 1
Red: 2
Orange: 3
Yellow: 4
Green: 5
Blue: 6
Violet: 7
Grey: 8
White: 9

Published: December 2025 | Author: TriVolt Editorial Team | Last Updated: February 2026

Understanding Resistor Color Codes

Resistor color codes are a standardized system used to identify the resistance value, tolerance, and sometimes temperature coefficient of resistors. This system was developed because resistors are often too small to print numerical values directly on them, and color bands provide a reliable, durable way to encode this information.

The color code system uses colored bands painted around the resistor body. Most resistors have four bands, though precision resistors may have five or six bands. Understanding how to read these color codes is essential for anyone working with electronics, from hobbyists to professional engineers.

How the Color Code Works

For a standard four-band resistor, the color bands represent:

  1. First Band: First significant digit of the resistance value
  2. Second Band: Second significant digit of the resistance value
  3. Third Band: Multiplier (power of 10)
  4. Fourth Band: Tolerance (percentage deviation from stated value)

The resistance value is calculated as: R = (First Digit × 10 + Second Digit) × Multiplier

Color Code Values

The standard color code uses ten colors to represent digits 0-9, plus additional colors for multipliers and tolerance:

ColorDigitMultiplierTolerance
Black0×1-
Brown1×10±1%
Red2×100±2%
Orange3×1,000-
Yellow4×10,000-
Green5×100,000±0.5%
Blue6×1,000,000±0.25%
Violet7×10,000,000±0.1%
Grey8×100,000,000±0.05%
White9×1,000,000,000-
Gold-×0.1±5%
Silver-×0.01±10%

Reading Resistor Color Codes

To read a resistor's value, start from the band closest to one end. The first two bands give the significant digits, the third band is the multiplier, and the fourth band (if present) indicates tolerance. Some resistors have a wider spacing before the tolerance band to help identify the reading direction.

Example 1: 1,000Ω (1kΩ) Resistor

Bands: Brown (1) - Black (0) - Red (×100) - Gold (±5%)

Calculation: (1 × 10 + 0) × 100 = 1,000Ω = 1kΩ

Value: 1,000Ω ± 5% (950Ω to 1,050Ω)

Example 2: 47,000Ω (47kΩ) Resistor

Bands: Yellow (4) - Violet (7) - Orange (×1,000) - Gold (±5%)

Calculation: (4 × 10 + 7) × 1,000 = 47,000Ω = 47kΩ

Value: 47,000Ω ± 5%

Example 3: 2.2Ω Resistor

Bands: Red (2) - Red (2) - Gold (×0.1) - Gold (±5%)

Calculation: (2 × 10 + 2) × 0.1 = 2.2Ω

Value: 2.2Ω ± 5%

Five-Band and Six-Band Resistors

Precision resistors often use five or six bands:

  • Five-Band: First three bands are significant digits, fourth is multiplier, fifth is tolerance
  • Six-Band: Same as five-band, with a sixth band indicating temperature coefficient

Five-band resistors provide higher precision (typically 1% or better tolerance) and allow for more precise resistance values.

Practical Applications

Resistor color codes are used throughout electronics for component identification. Being able to quickly read these codes is essential for:

  • Circuit Assembly: Identifying correct resistor values during circuit construction
  • Troubleshooting: Verifying resistor values in existing circuits
  • Inventory Management: Organizing and identifying resistors in component bins
  • Education: Learning electronics and understanding component values
  • Repair Work: Replacing faulty resistors with correct values

Tips for Using This Calculator

  • Select colors for the first three bands (required) to calculate resistance
  • The fourth band (tolerance) is optional but recommended for complete information
  • Results are displayed in appropriate units (Ω, kΩ, or MΩ)
  • Remember that tolerance indicates the range of possible values
  • For precision applications, verify resistor values with a multimeter
  • Always double-check color band readings, especially in poor lighting

Disclaimer

This calculator is provided for educational and informational purposes only. While we strive for accuracy, users should verify all calculations independently, especially for critical applications. We are not responsible for any errors, omissions, or damages arising from the use of this calculator.

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