19/07/2025 5:23 am
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I have a few resistors without any labels, and I want to figure out their resistance values using the colored bands printed on them. I know there’s a color code system, but I’m not entirely sure how to read it correctly—especially when there are four or five bands.
Could someone explain how to interpret the resistor color code, and maybe suggest a reliable method or chart to use for quick identification? Also, how do I tell which side to start reading from?
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21/07/2025 5:53 am
A good rule of thumb when reading resistor color codes is to start from the end where the color band is closest to the lead. That first band usually marks the most significant digit, so if one side has a band that's clearly closer to the edge than the other, that’s your starting point.
For instance, in many 4-band resistors, you’ll see something like red on one end and gold on the other. The gold band is usually spaced a bit farther from the edge, and since gold and silver are never used as the first digit, that’s a solid hint they mark the tolerance and should be read last.
Resistors can have up to 6 color bands, with the extra ones representing things like tolerance and temperature coefficient. These can be a bit trickier to read, but once you're familiar with the basic rules, it gets easier.
Here’s a quick breakdown:
4-Band Resistor
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1st Band = 1st digit
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2nd Band = 2nd digit
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3rd Band = Multiplier (i.e., how many zeros to add)
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4th Band = Tolerance (accuracy)
Example: Red (2), Violet (7), Orange (×1,000), Gold (±5%) → 27,000 ohms or 27kΩ ±5%
If you still find it tricky, you can use an online calculator to make things easier:
👉Resistor Color Code Calculator
