Choose the color bands of your resistor to instantly calculate its resistance value and tolerance range.
How a 5-band resistor code works
A 5-band resistor uses color stripes to encode its value without printed numbers. The first three bands are significant digits, the fourth band is the multiplier, and the fifth band is tolerance. This format provides more precision than a 4-band resistor because it includes a third significant digit.
For example, if the first three bands are Brown, Black, Black, that gives digits 1-0-0. If the multiplier band is Red (×100), the resistor value is 100 × 100 = 10,000 Ω, or 10 kΩ. If the tolerance band is Brown, the part is rated at ±1%.
5-band resistor color chart
| Color | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | ×1 | — |
| Brown | 1 | ×10 | ±1% |
| Red | 2 | ×100 | ±2% |
| Orange | 3 | ×1k | — |
| Yellow | 4 | ×10k | — |
| Green | 5 | ×100k | ±0.5% |
| Blue | 6 | ×1M | ±0.25% |
| Violet | 7 | ×10M | ±0.1% |
| Gray | 8 | ×100M | ±0.05% |
| White | 9 | ×1G | — |
| Gold | — | ×0.1 | ±5% |
| Silver | — | ×0.01 | ±10% |
Step-by-step manual decoding
1) Read from the correct side
The tolerance band is usually spaced farther away from the others. Start reading from the opposite side so the final band is tolerance.
2) Convert the first three bands to digits
- Band 1 = first digit
- Band 2 = second digit
- Band 3 = third digit
3) Apply the multiplier
Band 4 scales the 3-digit number by powers of ten (or by 0.1 / 0.01 for gold/silver multipliers).
4) Add tolerance range
Band 5 gives the allowable percentage variation from nominal value.
Worked examples
Example A: Brown-Black-Black-Red-Brown
Digits: 1, 0, 0 → 100. Multiplier: Red = ×100. Value: 100 × 100 = 10,000 Ω = 10 kΩ. Tolerance: Brown = ±1%. Final: 10 kΩ ±1%.
Example B: Red-Violet-Black-Gold-Red
Digits: 2, 7, 0 → 270. Multiplier: Gold = ×0.1. Value: 27 Ω. Tolerance: Red = ±2%. Final: 27 Ω ±2%.
Common mistakes to avoid
- Reversed reading direction: always locate the tolerance band first.
- Confusing gray and silver: gray is a digit/tolerance color, silver is usually multiplier/tolerance.
- Forgetting the third digit: 5-band is not decoded like 4-band.
- Ignoring tolerance in design: nominal value alone is not enough for tight analog circuits.
Why this calculator helps
When you're prototyping on a breadboard or sorting mixed resistor packs, visual decoding can be slow and error-prone. This calculator gives immediate nominal value, engineering-unit formatting (Ω, kΩ, MΩ), and min/max range from tolerance. It is especially useful for students, technicians, and hobbyists working with multimeters, microcontrollers, audio circuits, and sensor interfaces.