Resistor Color Code Calculator
Decode a 4-band resistor's color code into its resistance value and tolerance — no multimeter needed.
Resistance value
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Tolerance range —
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How it works
Value = (band1 × 10 + band2) × 10^(band3 multiplier); tolerance from band 4Frequently Asked Questions
How do I read resistor color bands?
The first two bands are significant digits, the third is a power-of-10 multiplier, and the fourth is tolerance: yellow-violet-red-gold reads 4, 7, ×100 = 4,700Ω (4.7kΩ) with ±5% tolerance.
What do the resistor color values mean?
Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Grey=8, White=9. The multiplier band uses the same digit colors as a power of 10, plus gold (×0.1) and silver (×0.01) for very low values.
What does the tolerance band tell me?
How much the actual resistance may vary from the marked value: gold is ±5%, silver ±10%, no band ±20%, and precision resistors often use brown (±1%) or red (±2%) instead.