Resistor Color Code Calculator
🔍 Find Color Bands by Resistance Value
Enter a resistance value to find the corresponding color bands.
📊 Resistor Color Code Reference Table
| Color | Digit | Multiplier | Tolerance | Temp Coeff (ppm/K) |
|---|---|---|---|---|
| Black | 0 | ×1 (10⁰) | — | 250 |
| Brown | 1 | ×10 (10¹) | ±1% | 100 |
| Red | 2 | ×100 (10²) | ±2% | 50 |
| Orange | 3 | ×1k (10³) | — | 15 |
| Yellow | 4 | ×10k (10⁴) | — | 25 |
| Green | 5 | ×100k (10⁵) | ±0.5% | 20 |
| Blue | 6 | ×1M (10⁶) | ±0.25% | 10 |
| Violet | 7 | ×10M (10⁷) | ±0.1% | 5 |
| Grey | 8 | ×100M (10⁸) | ±0.05% | 1 |
| White | 9 | ×1G (10⁹) | — | — |
| Gold | — | ×0.1 (10⁻¹) | ±5% | — |
| Silver | — | ×0.01 (10⁻²) | ±10% | — |
| None | — | — | ±20% | — |
📚 Understanding Resistor Color Codes
What is a Resistor Color Code?
Resistor color codes are a standardized system of colored bands painted on resistors to indicate their electrical resistance value and tolerance. This system was developed because many resistors are too small to have their values printed as numbers. The color code allows for quick identification of resistor values in electronic circuits.
How to Read Resistor Bands
To read a resistor's value, hold it so the grouped bands are on the left side. The tolerance band (usually gold or silver) should be on the right. Read the bands from left to right:
- 4-Band Resistors: 1st digit, 2nd digit, multiplier, tolerance
- 5-Band Resistors: 1st digit, 2nd digit, 3rd digit, multiplier, tolerance
- 6-Band Resistors: 1st digit, 2nd digit, 3rd digit, multiplier, tolerance, temperature coefficient
Resistance Calculation Formula
Where D₁, D₂, D₃ are the digit values (0-9) corresponding to each color band.
Example Calculations
Helpful Mnemonic
A popular mnemonic to remember the color sequence (Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Grey, White) is:
Temperature Coefficient (6-Band Resistors)
The sixth band on precision resistors indicates the temperature coefficient, measured in parts per million per Kelvin (ppm/K). This tells you how much the resistance changes with temperature. Lower values indicate more stable resistors, which are important for precision applications.