Resistor Color Code Calculator

Resistor Color Code Calculator turns the coloured bands on any resistor into a clear resistance value and tolerance — instantly and completely offline. Whether you are building a circuit, repairing a board or studying electronics, just pick the band colours and read the answer.

WHAT YOU CAN DO
• Decode 4-band, 5-band and 6-band resistors
• Tap each band to choose its colour from a labelled list
• See the resistance formatted in Ω, kΩ, MΩ or GΩ
• Read the tolerance and the resulting min–max value range
• Get the temperature coefficient on 6-band parts
• View a live drawing of the resistor with your chosen bands

EVERY BAND, COVERED
Significant-figure digits (black 0 through white 9), power-of-ten multipliers (×1 up to ×1G, plus gold ×0.1 and silver ×0.01), tolerances from ±0.1% to ±20%, and temperature coefficients in ppm/K — all built in and standards-correct.

LEARN AS YOU GO
A built-in Learn tab explains, in plain language, how the colour code works, which way to read a resistor, and a worked example. The Chart tab lists the full colour reference table so you can look up any band at a glance.

CLEAN AND FAST
A focused design in light and dark themes, a tiny download, no sign-in and no clutter. Everything runs on your device.

PRIVACY
The app collects no personal data and works fully offline — your inputs never leave your device. Ads are served by Google AdMob, which may use an advertising identifier (advertising ID) as described in Google's policies.

IMPORTANT
This tool is for general and educational use. Always confirm critical values with a multimeter or the part datasheet before relying on them in a circuit.

Download Resistor Color Code Calculator and read any resistor with confidence.