Resistor Color Code Calculator

How to read resistor color codes

Resistors use color bands to encode their value. For a 4-band resistor: bands 1 and 2 are the first two significant digits, band 3 is the multiplier (power of 10), and band 4 is tolerance. A 5-band resistor adds a third significant digit before the multiplier for greater precision. The standard color-to-digit mapping runs Black=0 through White=9; Gold and Silver are only used for tolerance (±5% and ±10%).

For related electronics calculations, see Ohm's Law Calculator.