Calculate resistor values from color bands. 4-band and 5-band support.
Resistor Color Code Calculator is a free, browser-based tool designed for students, professionals, and anyone who needs quick calculations. Calculate resistor values from color bands. 4-band and 5-band resistors. See resistance in ohms, kilohms, megaohms. Free online resistor calculator. Everything runs locally in your browser using JavaScript — no data is ever sent to a server, making it completely private and secure. The tool is designed to be intuitive and beginner-friendly while still offering advanced features for power users. It loads instantly with no installation required and works offline once loaded. Use it as often as you need — there are no daily limits, no watermarks, and no hidden fees.
Yes! Resistor Color Code Calculator is completely free with no signup required. It runs entirely in your browser — your data never leaves your device.
Simply enter your values in the input fields above and the results update instantly. No button clicks needed — everything calculates in real-time.
Absolutely. Resistor Color Code Calculator runs 100% client-side in your browser using JavaScript. No data is uploaded, stored, or shared with any server. Your privacy is guaranteed.