Calculators
Resistor Color Code Calculator
Decode 4-, 5-, and 6-band resistor color codes into resistance, tolerance, and temperature coefficient values locally.
Choose each resistor band in order. This calculator decodes 4-, 5-, and 6-band resistor color codes privately in your browser; nothing is uploaded or stored.
Read resistor bands without a chart or upload.
Choose the resistor’s bands in order to decode 4-band, 5-band, and 6-band color codes. The result shows resistance and tolerance; 6-band resistors also show their temperature coefficient in ppm/°C. Everything runs locally in your browser, so no band selections or results are uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
How do 4-band and 5-band resistor color codes differ?
A 4-band resistor uses two significant digit bands, a multiplier, and a tolerance band. A 5-band resistor uses three significant digit bands before the multiplier and tolerance bands, providing a more precise resistance value.
What does a 6-band resistor add?
A 6-band resistor uses the same three significant digits, multiplier, and tolerance as a 5-band resistor, plus a temperature-coefficient band. The temperature coefficient is shown in parts per million per degree Celsius (ppm/°C).
What do resistance and tolerance mean?
Resistance is the nominal opposition to electric current, shown in ohms, kilohms, megohms, or gigohms. Tolerance is the permitted variation from that nominal value; for example, ±5% means the actual measured resistance may vary by up to 5% either way.
Are my resistor bands or results sent anywhere?
No. The decoding and copy action run locally in your browser. CodeASystem does not upload or store the band selections or results.