Resistor Color Code Calculator
Decode resistor color bands to find the value, or find color bands for a given resistance. Supports 4, 5, and 6 band resistors.
Calculator
How to Use This Calculator
This calculator helps you decode the colored bands on through-hole resistors to find their resistance value, or find the correct color bands for a given resistance.
- Decode Mode — Select the colors from your resistor to find its value
- Find Colors Mode — Enter a resistance value to find the color bands
- Band Type — Choose between 4, 5, or 6 band resistors
The calculator shows the resistance value along with tolerance percentage and temperature coefficient (for 6-band resistors).
Resistor Color Code Chart
Each color represents a specific digit, multiplier, tolerance, or temperature coefficient:
| Color | Digit | Multiplier | Tolerance | Temp Coef |
|---|---|---|---|---|
| Black | 0 | ×1 | — | — |
| Brown | 1 | ×10 | ±1% | 100 ppm/°C |
| Red | 2 | ×100 | ±2% | 50 ppm/°C |
| Orange | 3 | ×1k | — | 15 ppm/°C |
| Yellow | 4 | ×10k | — | 25 ppm/°C |
| Green | 5 | ×100k | ±0.5% | 20 ppm/°C |
| Blue | 6 | ×1M | ±0.25% | 10 ppm/°C |
| Violet | 7 | ×10M | ±0.1% | 5 ppm/°C |
| Gray | 8 | ×100M | ±0.05% | 1 ppm/°C |
| White | 9 | ×1G | — | — |
| Gold | — | ×0.1 | ±5% | — |
| Silver | — | ×0.01 | ±10% | — |
| None | — | — | ±20% | — |
Common Examples
4-Band Resistor: 4.7kΩ ±5%
47 × 100 = 4,700Ω = 4.7kΩ
4-Band Resistor: 10kΩ ±5%
10 × 1,000 = 10,000Ω = 10kΩ
5-Band Resistor: 1kΩ ±1%
100 × 10 = 1,000Ω = 1kΩ
Understanding Band Types
4-Band Resistors
The most common type for general-purpose resistors. Bands represent:
- Band 1: First significant digit
- Band 2: Second significant digit
- Band 3: Multiplier (power of 10)
- Band 4: Tolerance (typically gold = ±5% or silver = ±10%)
5-Band Resistors
Used for precision resistors with three significant digits. Bands represent:
- Band 1: First significant digit
- Band 2: Second significant digit
- Band 3: Third significant digit
- Band 4: Multiplier
- Band 5: Tolerance (typically ±1% or ±2%)
6-Band Resistors
High-precision resistors that include a temperature coefficient band:
- Bands 1-3: Three significant digits
- Band 4: Multiplier
- Band 5: Tolerance
- Band 6: Temperature coefficient (ppm/°C)
Frequently Asked Questions
How do I know which end to start reading from?
The tolerance band (gold, silver, or a wider gap) is always on the right side. Start reading from the band closest to the left edge of the resistor. On 5 and 6 band resistors, the first band is often closer to one end.
What does the tolerance mean?
Tolerance indicates how much the actual resistance can vary from the marked value. A 10kΩ resistor with ±5% tolerance can be anywhere from 9,500Ω to 10,500Ω. Lower tolerance resistors are more precise but typically cost more.
Why are some colors hard to distinguish?
Brown, red, and orange can look similar under certain lighting. Gray and silver can also be confused. When in doubt, measure the resistor with a multimeter. Some resistors also fade or discolor over time.
What is the temperature coefficient?
The temperature coefficient (ppm/°C) indicates how much the resistance changes with temperature. A resistor with 100 ppm/°C will change 0.01% for every 1°C temperature change. Lower values indicate more stable resistors.
What are E-series values?
Resistors come in standard value series (E12, E24, E48, E96). The number indicates how many values per decade. E12 has 12 values (10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82) and is common for ±10% resistors. E96 has 96 values per decade for ±1% resistors.
Verify Your Component Selections
After calculating your component values, use Schemalyzer to verify your schematic design. Our AI-powered analysis catches common errors and suggests improvements.
Try Free Schematic Review