Blue Yellow Yellow Gold — 640 kΩ
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 kΩ
Range at ±5%
608 kΩ – 672 kΩ
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 | Yellow | Multiplier — ×10k |
| 4 | Gold | Tolerance — ±5% |
In a circuit
Across 5 V
7.81 µA · 39.1 µW · 1/8 W part
Across 12 V
18.8 µA · 225 µW · 1/8 W part
Surface-mount marking for the same value: 644.
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.