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Resistor Color Code Calculator
Read a resistor color code into resistance and tolerance, or enter an ohm value to find its nearest standard band pattern. Choose 4, 5 or 6 bands; six-band codes also show temperature coefficient.
How do you read a resistor color code?
Read the bands from the end opposite the tolerance band. The first two or three bands are significant digits, the next is the multiplier, then tolerance; a sixth band gives temperature coefficient. For example, brown-black-red-gold means 10 × 100 Ω = 1,000 Ω with ±5% tolerance.
Frequently asked questions
How do you read a resistor color code?
Read the bands from the end opposite the tolerance band. The first two or three bands are significant digits, the next is the multiplier, then tolerance; a sixth band gives temperature coefficient. For example, brown-black-red-gold means 10 × 100 Ω = 1,000 Ω with ±5% tolerance.
Are my values uploaded?
No. The color-code calculation runs in this browser; values are not uploaded or saved.
What does brown-black-red-gold mean?
Brown is 1, black is 0, red multiplies by 100, and gold means ±5% tolerance: 1,000 Ω ±5%.
What changes between 4-, 5- and 6-band resistors?
Four bands use two significant digits; five use three; six add a temperature-coefficient band.
Does reverse encoding guarantee an exact resistor value?
Not always. It selects the nearest value representable with the chosen band count and shows when rounding occurred.