Resistor color code calculator

Select the color ring by ring to read the resistance value, or enter the ohm value to find a representable color ring; all calculations are completed locally in the browser.

Query after selecting a color; the default examples are yellow, purple, orange, and gold.
Instructions

Choose 4, 5 or 6 bands. Starting at the first significant-digit band near one end, select each color in order. Four bands use two digits, a multiplier and a tolerance; five bands use three digits; six bands add a temperature coefficient. If orientation is uncertain, compare the reverse order only when it forms a valid code.

For example, yellow, purple, orange, and gold are 47 kΩ, ±5%, and the tolerance range is 44.65–49.35 kΩ; brown, black, black, red, and brown are 10 kΩ, ±1%.

Algorithms and Limitations

Resistance = significant digits × multiplier. Tolerance interval = nominal resistance × (1 ± tolerance percent). Reverse lookup enumerates the supported encodings; if there is no exact match, it shows the nearest lower and upper values, not E-series stock choices.

Only the publicly verifiable common colors listed here are supported. Uncolored tolerance, pink multipliers and unverified combinations are omitted; this is not a complete IEC 60062 implementation. No photo recognition, damaged-band inference, wattage or component rating.

For teaching only. With power off, verify a physical resistor using a suitable meter; faded or overheated bands can be misread. Consult the component datasheet and qualified personnel for real circuits.

DigiKey

Related tools

Resistor color code calculator

Select the number of rings and query direction. Color squares are labeled with text; reverse input accepts positive ohm values ​​and does not guarantee that the calculated resistor will be a purchasable resistor.

Settings