Resistor Color Code Calculator
Decode a resistor's color bands into its resistance and tolerance, or look up the correct band colors for a resistance value you already know. Supports 4-band and 5-band resistors.
Colors → value
Value → colors
Formula & band meaning
5-band: [digit 1][digit 2][digit 3] × [multiplier] ± [tolerance]
Example (4-band): brown, black, red, gold → 10 × 100 = 1000Ω ±5% (0.95kΩ–1.05kΩ)
1Worked example: brown–black–red–gold reads as digits 1, 0, multiplier ×100, giving 10 × 100 = 1,000Ω (1kΩ), ±5% tolerance.
Common questions
How is a 5-band resistor different from a 4-band one?
A 4-band resistor encodes 2 significant digits, a multiplier, and a tolerance. A 5-band resistor adds a third significant digit for tighter precision — common on 1% tolerance resistors and better.
Which band do I start reading from?
Start from the band closest to one end of the resistor — the tolerance band (usually gold or silver, sometimes brown) is normally the odd one out and set apart slightly, marking the end you read from.
What if there's no tolerance band at all?
A resistor with no tolerance band uses the default ±20% tolerance, per IEC 60062. This is uncommon on modern components but the calculator supports it via the "none" tolerance option.