Resistor Color Code Calculator
Select band colors to decode resistor value, or enter a value to find the color code.
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How to Read Resistor Color Codes
Resistor color codes use colored bands to indicate resistance value and tolerance. A standard 4-band resistor has two digit bands, a multiplier band, and a tolerance band.
The first two bands represent the first two digits of the resistance value. The third band is the multiplier (number of zeros to add). The fourth band indicates tolerance.
Gold tolerance (±5%) and brown tolerance (±1%) are the most common. When in doubt, orient the resistor so the gold or silver band is on the right side.
Standard resistors use color bands to encode resistance and tolerance. For 4-band resistors: band 1 and band 2 are the first two significant digits, band 3 is the multiplier (power of 10), band 4 is tolerance (gold = ±5%, silver = ±10%).
Color-to-digit mapping: Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Grey=8, White=9. A resistor with bands Red-Red-Orange-Gold reads: 2, 2, ×1000, ±5% = 22kΩ ±5%.
5-band resistors add a third significant digit before the multiplier, allowing precision values like 1.00kΩ (Brown-Black-Black-Brown-Brown for 100 × 10 = 1000Ω ±1%). High-precision resistors are usually 5-band.
The tolerance band determines acceptable variance. A 100Ω ±5% resistor can measure anywhere from 95Ω to 105Ω and still be in-spec. For sensitive circuits (audio, measurement), use 1% or better tolerance parts.
See also: Ohm's Law Calculator · LED Resistor Calculator