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Resistor Color Code Calculator

Decode 4-, 5-, and 6-band resistor color codes or enter a resistance to generate the bands. Check tolerance and, for 6-band resistors, temperature coefficient.

HelpReference

Interactive resistor calculator

Band count:

Type 4700, 4.7k, or 4.7 kΩ

Tolerance
Range0.95–1.05 kΩ
Resistor value1.0 kΩ ±5%

Read 4-, 5- and 6-band resistor color codes

Choose the band count, then select the observed colors to decode a resistor. You can also enter Resistance and its unit to generate bands. Reading direction, band roles and the complete color reference follow in the expandable instructions.

Worked color-band examples

Yellow–violet–red–gold gives 47 × 100 Ω = 4.7 kΩ at ±5%. Its limits are 4,700 × 0.95 = 4,465 Ω and 4,700 × 1.05 = 4,935 Ω.

For five bands, yellow–violet–black–brown–brown gives 470 × 10 Ω = 4.7 kΩ at ±1%, or 4,653–4,747 Ω. A sixth brown band specifies 100 ppm/K TCR, separately from the initial tolerance.

To generate the first example, choose 4 band, enter 4.7 kΩ and select ±5% tolerance. Reverse generation may round to the digits available in a format; review any nearest-value message separately from manufacturing tolerance.

Read markings on real resistors

These are decoded nominal values, not meter measurements of the photographed parts. Color and glare can make bands or characters ambiguous. Check the reading direction and the actual component; consult its datasheet or measure resistance when uncertain. In-circuit measurements can include parallel paths.

Four-band axial resistor with brown, green, orange and gold bands.

Four bands: 15 kΩ ±5%.

Read left to right: brown–green–orange–gold. Brown = 1, green = 5, orange = ×1,000: 15 × 1,000 Ω = 15,000 Ω. Gold indicates ±5%, giving a nominal tolerance interval of 14.25–15.75 kΩ.

Four-band axial resistor with brown, black, yellow and gold bands.

Four bands: 100 kΩ ±5%.

Brown–black–yellow–gold: 10 × 10,000 Ω = 100,000 Ω. Gold indicates ±5%, or 95–105 kΩ. Compare the yellow ×10,000 multiplier here with the orange ×1,000 band in the 15 kΩ example.

Five-band axial resistor with brown, black, black, red and brown bands.

Five bands: 10 kΩ ±1%.

Brown–black–black–red–brown: the first three bands give 100; red is ×100, so 100 × 100 Ω = 10,000 Ω. The final brown indicates ±1%, giving 9.90–10.10 kΩ. Five-band codes use three significant digits, unlike the two significant digits in four-band codes.

Six-band resistor with brown, black, black, red, brown and red bands.

Six bands: 10.0 kΩ ±1%, 50 ppm/°C.

Read left to right: brown–black–black–red–brown–red. The first three bands give 100; the fourth band, red, means ×100, so 100 × 100 Ω = 10,000 Ω = 10.0 kΩ. The fifth band, brown, indicates ±1%, giving 9.90–10.10 kΩ. The sixth band, red, indicates a temperature coefficient of 50 ppm/°C.

The sixth band describes temperature coefficient, not another resistance digit or tolerance band. A temperature coefficient of 50 ppm/°C corresponds to 0.005% per degree—about 0.5 Ω per °C for a 10 kΩ resistor. The calculator labels TCR in ppm/K; ppm/K and ppm/°C have the same numerical value for temperature changes. Check the component datasheet for the applicable temperature range.

Component photographs supplied by CircuitKitchen.

How calculations are checked

Automated checks cover digit/multiplier decoding, band roles, tolerance and TCR interpretation, resistance limits, reverse generation and representational rounding, unit handling and invalid inputs. The About page describes the original spreadsheet and hand-calculation process. These checks verify the marking conversions; they are not physical component measurements.

After identifying the resistance, use the LED series resistor calculator to evaluate an LED circuit.

How to use

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Decode or generate color bands

Select 4 band, 5 band or 6 band. Choose each band color to decode a resistor, or enter Resistance and its unit to generate bands in the selected format. Then choose the required Tolerance and, for six bands, TCR. Check the displayed resistance range.

Choose the band format

4-band resistors use two significant digits, a multiplier, and a tolerance band. This format is typically used for general-purpose resistors, especially parts with ±5% or ±10% tolerance.

5-band resistors use three significant digits, a multiplier, and a tolerance band. They are typically used for precision resistors—commonly ±1% or tighter—and for values that require three significant digits, such as 10.2 kΩ.

6-band resistors use the same bands as a 5-band resistor, plus a sixth band for temperature coefficient of resistance (TCR). This format is typically used when resistance stability over temperature is important, such as in precision measurement, sensing, or control circuits.

Band count alone does not guarantee a particular tolerance or performance level. Manufacturers may use different marking conventions for certain resistor series, so consult the datasheet when the component’s specifications are critical.

Find the reading direction

The tolerance band is commonly separated by a larger space and positioned near one end of the resistor. Begin reading from the opposite end. On a 6-band resistor, the TCR band follows the tolerance band. The labels beneath the resistor in this tool identify the function of each band.

About the standard

This tool implements the conventional four-, five- and six-band layouts and the supported color-role values in Vishay document 20143 (28-Aug-2009). Gray tolerance is ±0.05% in this chart. Extended colors or values absent from that chart are not offered; this is not a claim to implement every edition or manufacturer variant of IEC 60062.

Ambiguous or damaged markings

If direction or a color is uncertain, consult the part’s datasheet or measure the resistance. Do not guess a damaged band when choosing a replacement.

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Theory & formulas

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Significant digits and multiplier

For four bands, R = (10 × digit 1 + digit 2) × multiplier Ω. Five- and six-band codes use R = (100 × digit 1 + 10 × digit 2 + digit 3) × multiplier Ω.

Resistance limits are Rmin = Rnominal × (1 − tolerance / 100) and Rmax = Rnominal × (1 + tolerance / 100).

Temperature coefficient and conversion difference

The sixth band specifies TCR in ppm/K: fractional resistance change per kelvin. It is separate from initial manufacturing tolerance. Reverse generation may round an entered value to the digits available in the selected band format; the displayed nearest-value difference is a representation difference, not an extra tolerance.

Band layouts, in reading order
BandsMeaning
42 significant digits · multiplier · tolerance
53 significant digits · multiplier · tolerance
63 significant digits · multiplier · tolerance · TCR

Open color reference below.

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Color code reference

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Resistor color reference
ColorDigitMultiplierToleranceTCR
Black0×1——
Brown1×10±1%100 ppm/K
Red2×100±2%50 ppm/K
Orange3×1k—15 ppm/K
Yellow4×10k—25 ppm/K
Green5×100k±0.5%—
Blue6×1M±0.25%10 ppm/K
Violet7×10M±0.1%5 ppm/K
Gray8×100M±0.05%—
White9×1G——
Gold—×0.1±5%—
Silver—×0.01±10%—
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Sources and marking conventions

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This calculator uses the conventional four-band format with a tolerance band, or five/six bands with three significant digits. Band count alone does not identify every manufacturer’s convention; check the actual part documentation.

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SMD Resistor Code CalculatorDecode a surface-mount resistor marking.Parallel Resistor CalculatorCalculate the equivalent resistance of parallel resistors.