Resistor color bands are a quick way to identify resistance value and tolerance without a multimeter. This tool helps you decode 4-band and 5-band resistors, and it also generates the correct color bands from an ohms value. The built-in resistor preview makes the result easy to verify at a glance.
Use it for electronics repair, Arduino projects, PCB assembly, and component sorting—especially when you’re reading values from mixed resistor kits.
Usually the tolerance band (often gold or silver) is spaced slightly apart and sits on the right. Read from the opposite side toward the tolerance band.
4-band uses two significant digits; 5-band uses three significant digits for better precision.
Gold and silver are usually multipliers for fractional values (×0.1 and ×0.01) or tolerance bands (±5% and ±10%).
Resistors have tolerance. A 10kΩ ±5% resistor can measure anywhere from ~9.5kΩ to ~10.5kΩ and still be within spec.
It supports common 4-band and 5-band color codes. Some specialty resistors can use different systems (like 6-band with tempco).
Yes. The first bands are significant digits, then multiplier, then tolerance. Reading from the wrong side gives the wrong value.
For most hobby projects, ±5% is fine. For precision circuits, use ±1% or better depending on design requirements.
Values must be representable with available digits and multipliers. “Best match” rounds to the nearest valid band set.
No. Everything runs locally in your browser.
Use the preview to confirm band order, then measure with a multimeter if you suspect aging, heat damage, or incorrect reading direction.