Resistor color code calculator

Colour tables follow IEC 60062 and the preferred values follow IEC 60063. A three-band part carries no tolerance band, so it reads as ±20%, and twenty percent encodes nothing in reverse mode for the same reason. The E-series nearest value is a sanity check on the reading, not a promise that your part is that exact member; historical E24 parts also differ from the pure series formula in a few values (2.7, 3.0, 3.3 and others), which is why the table here lists the traditional E24 members. Band direction is not auto-detected in decode mode: read the bands left to right, tolerance band last.