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Resistor Color Code Calculator
Decode a four-band resistor into ohms, tolerance and the minimum and maximum resistance.
Decode resistor colour bands
Resistance: —
Tolerance: —
Range: —
How to use the Resistor Color Code Calculator
- Set the four colour bands of your resistor using the drop-downs.
- Read the resistance, tolerance and acceptable range in the result panel.
- Copy the decoded value with the Copy result button.
Features
- Decodes four-band resistors instantly
- Shows tolerance and the acceptable range
- All twelve standard band colours
- Runs locally, no uploads
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Frequently Asked Questions
Common questions about the free online resistor color code calculator.
The first two bands give the significant digits, the third band sets the multiplier and the
fourth band gives the tolerance in percent.
It means 1 kilo-ohm with 5 percent tolerance: brown is 1, black is 0, red multiplies by 100
and gold allows 5 percent either way.
Black is 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8 and white 9
in the first two bands.
The third band is the multiplier. Red means multiply by 100, orange by 1000 and gold means
divide by 10.
The fourth band is the tolerance, so gold means plus or minus 5 percent and silver means plus
or minus 10 percent.
A resistor is never exact, so a 1 kOhm 5 percent part can sit anywhere between 950 ohms and
1050 ohms.
Most common resistors have four bands. Precision types use five bands for an extra digit or
six bands to add a temperature coefficient.
This tool covers four-band resistors. A five-band part uses three digit bands before the
multiplier and tolerance bands.
No. The decoding happens entirely in your browser, so the values you select are never sent
anywhere.
Yes. It is completely free and unlimited, with no account, no sign-up and no usage limits of
any kind.
Last updated: October 10, 2026