Decode resistor colour bands to get resistance value and tolerance — supports 4-band and 5-band resistors, plus series and parallel combination calculations.
Enter your figures and click Calculate to see your results.
Select the colour of each band on your resistor in order — the calculator decodes the resistance value and tolerance.
Press the Calculate button. All results appear instantly — no page reload needed.
Results appear with all key values labelled. Use Copy to grab the result or Download to save a text report.
Yes — completely free with no sign-up required. All calculations run instantly in your browser.
Results use standard scientific and engineering formulas and are accurate to the precision shown.
Yes — fully responsive and works on all devices.
No — all calculations happen locally in your browser. Nothing is uploaded or stored.
Yes — use the Download button after calculating to save a text summary of your results.
