Resistor Color Code Calculator — Bands to Value & Back

For a 4-band resistor: the first two bands are significant digits, the third is a multiplier, and the fourth is tolerance. Example: Brown-Black-Red-Gold = 1, 0, ×100, ±5% = 1000Ω (1kΩ) with 5% tolerance. Color values: Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Grey=8, White=9.

4-band resistors have 2 significant digits + multiplier + tolerance (standard precision, typically ±5% or ±10%). 5-band resistors have 3 significant digits + multiplier + tolerance, offering more precision (commonly ±1% tolerance) — used where accuracy matters more, like in precision circuits and measurement equipment.

Gold = ±5%, Silver = ±10%, Brown = ±1%, Red = ±2%, no band = ±20%. Tolerance indicates how much the actual resistance may vary from the marked (nominal) value — a 100Ω resistor with ±5% tolerance could actually measure anywhere from 95Ω to 105Ω.