Decode 4-band, 5-band, and 6-band resistors instantly with our interactive visual calculator. Select colors to find resistance, or enter a value to find the color code.
Resistors are the most fundamental component in electronics — they control current flow, divide voltages, set bias points, and protect sensitive components. Every through-hole resistor uses a standardized color band system to indicate its resistance value, tolerance, and sometimes temperature coefficient. Learning to read these codes is an essential skill for any electronics hobbyist, student, or engineer.
The resistor color code was established by the EIA (Electronic Industries Alliance) and uses a simple system: each color represents a digit from 0 to 9. The bands are read from left to right, starting from the band closest to one end of the resistor. The first bands represent significant digits, followed by a multiplier, and finally the tolerance.
The multiplier band indicates how many zeros to add (or the power of 10 to multiply by). Black = ×1 (no zeros), Brown = ×10, Red = ×100, Orange = ×1K, Yellow = ×10K, Green = ×100K, Blue = ×1M, Violet = ×10M. Special cases: Gold = ×0.1 and Silver = ×0.01, used for sub-ohm resistors (like 4.7Ω or 0.47Ω).
Tolerance tells you how close the actual resistance is to the labeled value. Common tolerances and their colors: Brown = ±1%, Red = ±2%, Green = ±0.5%, Blue = ±0.25%, Violet = ±0.1%, Gold = ±5%, Silver = ±10%, None = ±20%. Most resistors you encounter will have either gold (±5%) or brown (±1%) tolerance bands.
4-band resistors provide 2-digit precision — they can only represent values from the E12 or E24 standard series (12 or 24 values per decade). Typical tolerance is ±5% (gold). 5-band resistors provide 3-digit precision — they represent values from the E48, E96, or E192 series. Typical tolerance is ±1% (brown) or ±2% (red). In modern electronics, 5-band resistors are more common because precision has become inexpensive.
A 6-band resistor adds a temperature coefficient (TC) band — this indicates how much the resistance changes with temperature, measured in ppm/°C (parts per million per degree Celsius). Brown = 100 ppm/°C, Red = 50 ppm/°C, Orange = 15 ppm/°C, Yellow = 25 ppm/°C, Blue = 10 ppm/°C, Violet = 5 ppm/°C. Lower TC is better for precision applications. Most standard resistors have a TC of 100–200 ppm/°C.
Resistors aren't available in every possible value — they follow standardized series. The E12 series has 12 values per decade: 1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2. The E24 series has 24 values and is the most common for ±5% resistors. The E96 series has 96 values per decade for ±1% precision resistors. When designing circuits, always check that your calculated value exists in the appropriate E-series, or use the nearest standard value.