Tip: This tool rounds to the nearest representable code for your selected band type.
What this resistor color code calculator does
This calculator converts a numeric resistor value (in ohms) into a standard resistor color code sequence. If you've ever looked at a resistor and tried to decode those colored rings, this tool does the reverse: you enter a resistance value, and it tells you which colors to use.
It supports both 4-band and 5-band formats, includes configurable tolerance, and displays the final color bands in the correct order.
How resistor color coding works
4-band resistors
- Band 1: First significant digit
- Band 2: Second significant digit
- Band 3: Multiplier
- Band 4: Tolerance
5-band resistors
- Band 1: First significant digit
- Band 2: Second significant digit
- Band 3: Third significant digit
- Band 4: Multiplier
- Band 5: Tolerance
Example: 4.7kΩ in 4-band format is usually represented as Yellow, Violet, Red, Gold (47 × 10², ±5%).
Digit and multiplier reference
| Color | Digit | Multiplier |
|---|---|---|
| Black | 0 | ×1 |
| Brown | 1 | ×10 |
| Red | 2 | ×100 |
| Orange | 3 | ×1,000 |
| Yellow | 4 | ×10,000 |
| Green | 5 | ×100,000 |
| Blue | 6 | ×1,000,000 |
| Violet | 7 | ×10,000,000 |
| Gray | 8 | ×100,000,000 |
| White | 9 | ×1,000,000,000 |
| Gold | - | ×0.1 |
| Silver | - | ×0.01 |
Practical examples
Example 1: 220Ω (4-band)
220Ω becomes 22 × 10¹, so the bands are Red, Red, Brown, then tolerance (often Gold for ±5%).
Example 2: 10kΩ (5-band)
10kΩ becomes 100 × 10² in 5-band format, so the code is Brown, Black, Black, Red plus tolerance.
Example 3: 1MΩ (4-band)
1,000,000Ω becomes 10 × 10⁵, so the bands are Brown, Black, Green plus tolerance.
Common mistakes to avoid
- Mixing up multiplier and digit meanings.
- Using the wrong band count (4-band vs 5-band parts).
- Ignoring tolerance, which affects acceptable resistance range.
- Entering a value not representable exactly with selected band precision.
Why this is useful for electronics work
Whether you're prototyping on a breadboard, sorting resistor kits, repairing a board, or teaching electronics fundamentals, fast color-code conversion saves time and reduces wiring mistakes. This tool is especially handy when moving between schematic values and physical components.