Resistor Colour Code Calculator

Hold the resistor so the band closest to one end is on the left. Each colour corresponds to a digit (0–9). On a 4-band resistor the first two bands are digits, the third is the ×10 multiplier and the fourth is the tolerance. On a 5-band resistor the first three bands are digits, the fourth is the multiplier and the fifth is the tolerance. A 6-band resistor adds a temperature coefficient band at the end.

4-band resistors give two significant digits and a tolerance of typically 5% or 10%. 5-band resistors add a third significant digit, allowing tighter tolerances (1% or better) and more precise values. 6-band resistors add a temperature coefficient band (in ppm/°C) and are used in precision or temperature-sensitive circuits.

Gold and silver can appear as multipliers (×0.1 and ×0.01 respectively) on the multiplier band, or as tolerances (±5% gold, ±10% silver) on the tolerance band. If your resistor has a gold or silver band, it's always either the multiplier or the tolerance — never a digit.

Resistors are manufactured in preferred-value series (E6, E12, E24, E48, E96, E192) that are spaced logarithmically. This means the gap between adjacent values is roughly proportional to the tolerance, so stocking a limited set still covers every real-world requirement to within tolerance. E12 (10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 per decade) is the most common for 10% parts; E24 is used for 5%.

No. The first band represents the leading significant digit, which would be zero if black were allowed. A valid first band is brown through white (values 1–9).

Look for the band closest to one end of the resistor body — that's the first band. If the spacing looks symmetrical, the tolerance band is often gold or silver which helps identify the far end. If in doubt, try reading it both ways and pick the sequence that gives you a sensible preferred value.