Resistors

Decode the bands without second-guessing your eyes.

Choose the first two digits, multiplier and tolerance band to identify a standard four-band resistor.

Four-band order

Two digits, multiplier, tolerance.

For red-violet-red-gold, the first two digits are 2 and 7; red multiplies by 100; gold means ±5%. The answer is 2,700 Ω ±5%, commonly written 2.7 kΩ.

Five- and six-band precision resistors use a different arrangement; check the maker’s reference if your resistor has more bands.