Resistor Color Code Calculator

FAQ

How do you read a resistor color code?

Read the bands starting from the end where they sit closest together. The first bands give the significant digits (two on a 4-band, three on a 5 or 6-band), the next band is the multiplier (a power of ten), then comes the tolerance. Enter each color into the calculator and it applies the IEC 60062 table directly.

What is the difference between 4, 5 and 6 bands?

A 4-band resistor encodes two digits, a multiplier and a tolerance. The 5-band version adds a third significant digit, so higher precision (often plus or minus 1 percent). The 6th band gives the temperature coefficient in ppm/K, which matters when thermal drift counts. Pick the right band count at the top of the calculator.

What do the gold and silver bands mean?

On the multiplier band, gold means x0.1 and silver x0.01, used for small values (a few ohms and below). On the tolerance band, gold means plus or minus 5 percent and silver plus or minus 10 percent, the common tolerances on low-cost parts. So the same color means different things depending on its position.

Which way round do you read the bands?

The tolerance band (often gold or silver) sits slightly offset toward one end: put it on the right and read left to right. If both ends look symmetric, usually only one direction yields a standard value (the other gives a non-standard number). When in doubt, confirm the reading with a multimeter.

What is the 6th band for?

The 6th band is the temperature coefficient in ppm/K: how much the resistance shifts per degree. Brown is 100 ppm/K, red is 50, and so on. It matters for precision circuits (references, measurement bridges) where thermal drift would corrupt the result, but it is secondary for most general-purpose uses.