Resistor Color Code Calculator
Decode resistor color bands to determine resistance values. Calculate resistance, tolerance, and temperature coefficient from 4, 5, or 6 band resistors.
Understanding Resistor Color Codes
Resistor color codes are a standardized way to indicate the resistance value, tolerance, and sometimes temperature coefficient of resistors. This system uses colored bands painted on the resistor body to represent numerical values.
Different Band Systems
Resistors commonly come with 4, 5, or 6 color bands, each providing different levels of precision and information:
- 4-Band Resistors: The most common type, with two digits, a multiplier, and a tolerance band
- 5-Band Resistors: Provide higher precision with three digits, a multiplier, and a tolerance band
- 6-Band Resistors: Add a temperature coefficient band to the 5-band system
Color Code Values
Each color represents specific values depending on its position on the resistor:
Significant Figures (1st, 2nd, and 3rd bands)
Black (0), Brown (1), Red (2), Orange (3), Yellow (4), Green (5), Blue (6), Violet (7), Grey (8), White (9)
Multiplier (3rd band for 4-band, 4th band for 5 and 6-band resistors)
Black (×1), Brown (×10), Red (×100), Orange (×1k), Yellow (×10k), Green (×100k), Blue (×1M), Violet (×10M), Grey (×100M), White (×1G), Gold (×0.1), Silver (×0.01)
Tolerance (4th band for 4-band, 5th band for 5 and 6-band resistors)
Brown (±1%), Red (±2%), Green (±0.5%), Blue (±0.25%), Violet (±0.1%), Grey (±0.05%), Gold (±5%), Silver (±10%), None (±20%)
Temperature Coefficient (6th band only)
Brown (100 ppm/°C), Red (50 ppm/°C), Orange (15 ppm/°C), Yellow (25 ppm/°C), Blue (10 ppm/°C), Violet (5 ppm/°C)
How to Read Resistor Color Codes
Follow these steps to read a resistor's color code:
- Identify the number of bands on the resistor (usually 4, 5, or 6)
- Orient the resistor with the tolerance band (gold or silver) to the right
- Read the first two or three bands (from left) as significant digits
- Apply the multiplier from the next band
- Note the tolerance (and temperature coefficient for 6-band resistors)
Applications
Understanding resistor color codes is essential for:
- Working with electronic circuits and components
- Circuit design and prototyping
- Troubleshooting and repair of electronic equipment
- Electronics education and training