A 4-band resistor encodes a 2-digit value: two digit bands, then a multiplier, then tolerance. A 5-band resistor encodes a 3-digit value for more precision: three digit bands, then multiplier, then tolerance. Read a 5-band resistor's third band as a multiplier by mistake and the result is off by a factor of ten or more.
Resistor color code calculator, 4-band or 5-band
Toggle between 4-band and 5-band and the calculator shows the right number of digit bands automatically — pick each band's color from a dropdown and the resistance updates instantly, following the standard EIA-RS-279 color code.
Resistor color code chart, as a live visual
Alongside the dropdowns, a visual preview shows the actual band colors on a resistor body — useful for double-checking against a resistor in hand rather than just trusting a number.
How to read resistor colors, gold and silver as multipliers
Gold means ×0.1 and silver means ×0.01 when used as the multiplier band — used for resistors under 10 ohms, and easy to misread as tolerance bands if you're not expecting them there.
