Electronics Tools
Resistor Color Code Calculator
Decode 4-band and 5-band resistor color codes into resistance and tolerance. Use it when reading through-hole resistors in Arduino, ESP32, sensor, and breadboard circuits.
What this tool doesConverts resistor band colors into an ohm value and tolerance range.
Band orderRead from the end with grouped bands. The tolerance band is usually separated from the digit bands.
Practical noteMeasure with a multimeter when the part is old, heat-stressed, or still soldered into a circuit.
Calculator
Results
Resistance value
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Tolerance
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| Color | Digit | Multiplier | Tolerance |
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How the Calculation Works
For a 4-band resistor, the first two bands are significant digits. For a 5-band resistor, the first three bands are significant digits. The next band is the multiplier, and the final band gives tolerance.
4-band: value = (10 x digit1 + digit2) x multiplier
5-band: value = (100 x digit1 + 10 x digit2 + digit3) x multiplier
Practical Notes
- Gold and silver are multiplier and tolerance colors, not significant digit colors.
- Brown, red, green, blue, and violet tolerance bands are common on precision resistors.
- If the color bands are faded or ambiguous, confirm the value with a meter.