4-Band Resistor Color Code Calculator

Result

Nominal Value: 10.00Ω

Tolerance Range: 9.50Ω to 10.50Ω

Understanding 4-Band Resistor Color Codes

1. Color Code System

The 4-band color code system is the most common method for marking resistance values on through-hole resistors. Each band represents a specific value:

  • 1st Band: First significant digit
  • 2nd Band: Second significant digit
  • 3rd Band: Multiplier (number of zeros)
  • 4th Band: Tolerance

2. Reading Direction

To correctly read a 4-band resistor:

  • Hold the resistor with the gold or silver band to the right
  • Read the colors from left to right
  • The tolerance band is typically wider or separated
  • Gold and silver are only used for multiplier and tolerance bands

3. Color Values

Significant Digits (1st & 2nd Bands)

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

Multiplier (3rd Band)

  • Black: ×1
  • Brown: ×10
  • Red: ×100
  • Orange: ×1k
  • Yellow: ×10k
  • Green: ×100k
  • Blue: ×1M
  • Violet: ×10M
  • Gold: ×0.1
  • Silver: ×0.01

4. Tolerance Values

The fourth band indicates the tolerance range:

  • Brown: ±1%
  • Red: ±2%
  • Gold: ±5%
  • Silver: ±10%
  • No Band: ±20%

5. Applications

4-band resistors are commonly used in:

  • General purpose electronic circuits
  • Hobbyist projects
  • Educational applications
  • Prototype development
  • Non-critical circuit applications

6. Practical Tips

When working with 4-band resistors:

  • Use a multimeter to verify values when precision is critical
  • Consider environmental factors that may affect resistance
  • Store resistors in proper conditions to maintain markings
  • Account for tolerance in circuit design

Quick Reference

Value Calculation

Value = (D1 × 10 + D2) × 10^M

D1 = First digit
D2 = Second digit
M = Multiplier

Common Values

  • 1.0Ω - Brown, Black, Gold
  • 10Ω - Brown, Black, Black
  • 100Ω - Brown, Black, Brown
  • 1kΩ - Brown, Black, Red
  • 10kΩ - Brown, Black, Orange
  • 100kΩ - Brown, Black, Yellow
  • 1MΩ - Brown, Black, Green