How the resistor color code works
Through-hole resistors are too small to print numbers on, so their value is marked with painted bands. Each color stands for a number. To read a resistor, orient it so the slightly separated tolerance band is on the right, then read the bands from left to right.
On a 4-band resistor the first two bands are significant digits, the third is the multiplier and the fourth is the tolerance. On a 5-band resistor there are three significant-digit bands, then the multiplier, then the tolerance — the extra digit gives more precision for tight-tolerance parts.
Color code reference
| 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% |
| Grey | 8 | ×100M | ±0.05% |
| White | 9 | ×1G | — |
| Gold | — | ×0.1 | ±5% |
| Silver | — | ×0.01 | ±10% |
| None | — | — | ±20% |
Reference note: values follow the standard IEC 60062 resistor color code. Most everyday resistors use brown, red, gold or silver tolerance bands; the tighter tolerances (green, blue, violet, grey) appear mainly on 5-band precision parts.
Frequently asked questions
- How do I read a resistor color code?
- Hold the resistor with the tolerance band (often gold or silver) on the right, then read left to right. The first bands are significant digits, the next band is the multiplier, and the last band is the tolerance. Combine the digits and multiply to get ohms.
- What is the difference between 4-band and 5-band resistors?
- A 4-band resistor has two digit bands, a multiplier and a tolerance. A 5-band resistor adds a third digit band for more precision, giving three digit bands, a multiplier and a tolerance.
- What does the gold band mean?
- Gold means multiply by 0.1 when it is the multiplier band, or ±5% when it is the tolerance band. Silver similarly means ×0.01 or ±10%.
- How do I find the multiplier?
- The multiplier is the power of ten you multiply the digits by: black ×1, brown ×10, red ×100, orange ×1k, yellow ×10k, green ×100k, blue ×1M, plus gold ×0.1 and silver ×0.01.
- What is tolerance on a resistor?
- Tolerance is how far the actual resistance may stray from the nominal value: brown ±1%, red ±2%, green ±0.5%, gold ±5%, silver ±10%, no band ±20%. A 100Ω ±5% part can read 95Ω to 105Ω.
- Which end of the resistor do I read from?
- Read from the end where the bands are grouped closer together. The tolerance band usually sits slightly apart, so put it on the right and read the rest left to right.