Blue Yellow Brown Gold — 640 Ω
Read left to right, starting from the end where the bands are grouped. The gold band is the tolerance and always sits alone at the far end.
Value
640 Ω
Range at ±5%
608 Ω – 672 Ω
Standard value
Non-standard
No E24 part carries this value — check you are reading from the right end.
What each band says
| Band | Colour | Meaning |
|---|---|---|
| 1 | Blue | 1st digit — 6 |
| 2 | Yellow | 2nd digit — 4 |
| 3 | Brown | Multiplier — ×10 |
| 4 | Gold | Tolerance — ±5% |
In a circuit
Across 5 V
7.81 mA · 39.1 mW · 1/8 W part
Across 12 V
18.8 mA · 225 mW · 1/2 W part
Surface-mount marking for the same value: 641.
If you misread one band
Brown and red, or orange and red, are easy to confuse under a desk lamp. These are the codes one band away from this one.