How the Bands Work
The first two bands (three on a 5-band resistor) are digits. The next band multiplies them by a power of ten, and the last is the tolerance. Brown, black, orange is 1, 0, ×1,000: 10 kΩ. Red, red, brown is 2, 2, ×10: 220 Ω.
Resistors are made in preferred values (IEC 60063) so that the tolerance ranges of neighboring values meet. The ±10% series has 12 values per decade (E12), ±5% has 24 (E24), and ±1% has 96 (E96). If a reading isn’t a preferred value, check whether you’re reading from the wrong end.
