What the tool does, how to run it, and what to expect from the result.
The first 2 bands are digits, the 3rd is a multiplier (a power of 10), and the 4th is the tolerance. Resistance = (digit 1 x 10 + digit 2) x 10^multiplier. Band 1 is the one closest to either end of the resistor; if a reading looks implausible, try reading the bands in the opposite order.
A quick way to understand who this helps, what it solves, and where it connects next.
Hobbyists, students, and engineers reading a resistor by its color bands.
Decoding a 4-band resistor color code into an ohm value.
Short answers for the questions people usually have before trying a utility like this.
Yes. It is completely free, with no sign-up and no usage limits.
This calculator covers the more common 4-band code. A 5-band resistor adds a 3rd digit band for tighter precision; the multiplier and tolerance bands work the same way.
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Pick the 4 band colors on a resistor to read its resistance and tolerance.
1 kΩ±1% tolerance
Reading order matters: band 1 is closest to one end of the resistor. If a reading looks wrong, try the bands in reverse order.