Resistor Color-Code Reader

Bands 1 and 2 are the two significant digits, band 3 is the multiplier (how many zeros to add), and band 4 is the tolerance. Yellow–violet–red–gold reads 47 × 100 = 4,700 Ω = 4.7 kΩ, ±5%.

4-band resistors have 2 significant digits and a tolerance band (the common hobbyist type). 5-band resistors add a third significant digit for precision values. 6-band resistors add a sixth band: the temperature coefficient (TCR), in ppm/K.

As the multiplier band, gold means ×0.1 and silver means ×0.01 — used for sub-10 Ω values. As the tolerance band, gold means ±5% and silver means ±10%. They never appear as digit bands.

Read from the end where the digit bands are — the tolerance band (gold, silver, brown, red, or green) sits slightly apart from the others at the far end. If unsure, the group of 3–4 tightly spaced bands is the value end.

TCR is the sixth band on precision resistors: how much the resistance drifts per degree Celsius, in parts per million per kelvin. A 100 ppm/K resistor changes about 0.01% per °C.