Resistor Color Code

Read a resistor's value from its color bands: pick the colors - get the resistance, tolerance and TCR. Supports 4, 5 and 6 bands, everything runs in your browser.

Resistance
Tolerance
Range (min - max)

Read the bands from the side where they sit closer to the edge of the body: the last band (tolerance) is set apart from the rest and is often gold or silver.

Color code reference

ColorDigitMultiplierToleranceTCR, ppm/°C
Black0×1
Brown1×10±1%100
Red2×100±2%50
Orange3×1 kΩ15
Yellow4×10 kΩ25
Green5×100 kΩ±0.5%
Blue6×1 MΩ±0.25%10
Violet7×10 MΩ±0.1%5
Grey8±0.05%
White9
Gold×0.1±5%
Silver×0.01±10%
How to read

On a 4-band resistor the first two bands are digits, the third is the multiplier and the fourth is the tolerance. Precision resistors with 5 bands have three digit bands; 6-band resistors add the TCR - the temperature coefficient of resistance (how many ppm the resistance drifts per degree). Example: brown-black-red-gold is 10 × 100 = 1 kΩ ±5%.

Which side to read from

The first band is closer to the edge of the body, and the tolerance band is separated from the group by a wider gap. When in doubt, read it both ways: usually only one direction gives a standard E24-series value (1.0, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2.0, 2.2, 2.4, 2.7, 3.0 and so on). The most reliable check is a multimeter.

See also