4-Band Resistor Color Code Calculator

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

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