Resistor Calculator & Codes

Identify resistors, explore circuits and organize your components with 12 practical tools in a clear Material 3 interface. All tools are free, supported by ads, and calculations run locally on your device. READ AND CONVERT • Decode 3, 4, 5 and 6 color bands, or turn a resistance value into bands. • Choose colors with their electrical values, using the modern IEC color code. • See when a value is approximate or cannot be represented. • Decode SMD markings, R notation and EIA-96 codes. • Use a camera image or photo to assist with band identification. Crop, rotate and adjust the colors; manual confirmation is required before saving. CALCULATE AND SELECT • Solve Ohm’s law, series, parallel and mixed resistor networks. • Design loaded and unloaded voltage dividers and LED resistors. • Check power, tolerance, measured values and temperature effects. • Find preferred values and resistor combinations using exact E6, E12, E24, E48, E96 and E192 tables. KEEP YOUR WORK • Save calculations, add favorites and reuse previous inputs. • Edit a local component inventory with quantities and notes. • Preview and validate JSON backups before merging or replacing data. • Share results as text, PDF or paginated PNG images without a watermark; export inventory as CSV. Switch between light and dark themes and seven languages: English, Spanish, Portuguese, French, Italian, German and Japanese. Photo identification is assisted, not a guaranteed measurement. Confirm the bands and component specifications before using a result in a real circuit.

Added Indonesian, Vietnamese and Turkish. The in-app PrismaLab recommendations are now available in all ten supported languages.