A 1kΩ ±5% resistor, decoded free and instant.
Standard resistors are marked with colored bands instead of printed numbers, following the EIA color code. A 4-band resistor has two significant-digit bands, a multiplier band, and a tolerance band; a 5-band resistor adds a third significant digit for finer precision, common on more precise resistors.
Each color maps to a digit (black=0 through white=9), and the multiplier band's color tells you how many zeros to add (or, for gold and silver, a fractional multiplier below 1). The tolerance band's color separately indicates how far the actual resistance may vary from the marked value — gold means ±5%, a very common tolerance on everyday resistors.
The tolerance band (commonly gold or silver) is usually spaced slightly apart from the others, near one end — read the bands starting from the opposite end.
A 5-band resistor has one extra significant-digit band, giving more precise values (three digits instead of two) before the multiplier — common on resistors with tighter tolerances like ±1% or better.
The same color can mean different things depending on which band position it’s in — gold as a multiplier means ×0.1, while gold as the tolerance band means ±5%. Position matters, not just color.