How to use it
- Choose the band count.
- Select digit colors in reading order, followed by multiplier and tolerance.
- Decode the resistor and review the nominal, minimum and maximum values.
Resistor Color Code Calculator
Decode a 4-band or 5-band resistor value and tolerance range.
Important: This calculator is for educational and estimation purposes only. It is not electrical safety, installation, engineering, or code-compliance advice. Always consult a qualified electrician or engineer for real-world electrical work.
About the Resistor Color Code Calculator
This decoder converts common 4-band and 5-band resistor markings into nominal resistance and tolerance limits.
How it works
Four-band codes use two significant digits; five-band codes use three. The multiplier scales that number, and tolerance defines the expected percentage range.
Example
Brown, black, red and gold represents 10 × 100 = 1,000 Ω with ±5% tolerance, or an expected 950–1,050 Ω range.
Notes
Band orientation and colors can be difficult to identify. Confirm values with component documentation and suitable measurement practices.