How the color code works
The colored bands spell out the resistance: two (or three) digit bands, one multiplier band, and a tolerance band. A 6-band part adds a temperature coefficient. Yellow-violet-red-gold reads as 4 7 ×100 = 4.7 kΩ ±5%. Five-band resistors carry three digit bands for 1% precision parts — brown-black-black-red-brown is 100 ×100 = 10 kΩ ±1%.
The color table
| Color | Digit | Multiplier | Tolerance | Temp. coeff. |
|---|---|---|---|---|
| Black | 0 | ×1 | — | — |
| Brown | 1 | ×10 | ±1% | 100 ppm/K |
| Red | 2 | ×100 | ±2% | 50 ppm/K |
| Orange | 3 | ×1 k | — | 15 ppm/K |
| Yellow | 4 | ×10 k | — | 25 ppm/K |
| Green | 5 | ×100 k | ±0.5% | — |
| Blue | 6 | ×1 M | ±0.25% | 10 ppm/K |
| Violet | 7 | ×10 M | ±0.1% | 5 ppm/K |
| Gray | 8 | ×100 M | ±0.05% | — |
| White | 9 | ×1 G | — | — |
| Gold | — | ×0.1 | ±5% | — |
| Silver | — | ×0.01 | ±10% | — |
A common mnemonic for the digit order: Better Be Right Or Your Great Big Venture Goes West (black, brown, red, orange, yellow, green, blue, violet, gray, white).
Frequently asked questions
- Which end do I read from?
- Start from the band nearest a lead end; the tolerance band is usually set apart by a wider gap and is often gold or silver — colors that never appear as a first digit. If a reading looks absurd (like 0.15 Ω on a signal board), try it the other way around.
- Why do precision resistors have five bands?
- Three digit bands give three significant figures — you can't express 4.99 kΩ (an E96 value) with only two digits. Most 1% metal-film parts (the blue-bodied ones) use the 5-band code.
- What's a single black band?
- A zero-ohm jumper — a wire link in a resistor package so automated assembly machines can place it.
- What is the 6th band for?
- Temperature coefficient: how much the value drifts per kelvin, in parts per million. 100 ppm/K (brown) is ordinary; 15–25 ppm/K appears on precision parts.
- Need a standard value to aim for?
- The resistor calculator finds the nearest E12/E24/E96 values and combinations for any target.