What is the Resistor Color Code Calculator?
This resistor color code calculator translates manually selected bands on a color-banded axial resistor into its nominal resistance, percentage tolerance and minimum/maximum values at that tolerance. Four bands encode two significant digits, a multiplier and tolerance. Five bands add a third significant digit. Six bands additionally encode a temperature coefficient of resistance, or TCR.
It is a band decoder, not a photo recognizer or a test of whether a component is healthy. SMD number codes, zero-ohm jumpers, three-band parts and special manufacturer markings need a different identification method. The displayed diagram is a schematic preview of the selected colors, not a photograph of your actual part.
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Optional magnifying lamps (paid link) can make small bands easier to inspect. Read the printed datasheet when identification is uncertain; no purchase is required.
How to read 4, 5 and 6 band resistor color codes
- Count the bands and choose the 4-, 5- or 6-band arrangement.
- Identify the reading direction from the component’s band spacing and manufacturer guidance.
- Select the first two digit colors. Five- and six-band modes also require the third digit.
- Select the multiplier and tolerance colors. Six-band mode also requires the TCR color.
- Calculate, then compare the nominal value, tolerance interval and labeled band preview.
The first significant digit cannot be black in this tool. Gold, silver and pink are multiplier colors rather than significant digits. Each selector names the color and its meaning, so identification does not depend only on seeing the colored preview. Switching band count clears the previous result and uses only the fields for the chosen mode.
For a measurement check, optional digital multimeters (paid link) should be used on an isolated, unpowered component with suitable technique and instrument range. An in-circuit reading can differ because other paths may be connected. The Series & Parallel Resistor Calculator explains how connected paths change equivalent resistance.
Resistor color code formula and tolerance range
5 or 6 bands: R = (100 × digit 1 + 10 × digit 2 + digit 3) × 10^multiplier
Minimum = R × (1 − tolerance/100)
Maximum = R × (1 + tolerance/100)
The result is first calculated in ohms, then displayed in Ω, kΩ, MΩ or GΩ. One kilohm is 1,000 Ω; one megohm is 1,000,000 Ω. Display values use up to seven significant digits while calculation retains normal floating-point precision.
The tolerance interval represents the marked initial resistance tolerance. It does not combine temperature drift, aging, voltage coefficient, meter uncertainty or lead resistance. The sixth band is reported separately in ppm/K; a one-kelvin temperature change equals a one-degree-Celsius temperature difference, but TCR alone does not establish actual operating resistance.
Resistor color code examples: 4 band, 5 band and 6 band
Four-band example: brown, black, red, gold. Brown and black give 10; red means ×100. Nominal resistance is 10 × 100 = 1,000 Ω, or 1 kΩ. Gold gives ±5%, so the nominal tolerance interval is 950–1,050 Ω.
Five-band example: brown, black, black, red, brown. The significant number is 100, the multiplier is ×100 and tolerance is ±1%. The value is 10,000 Ω, or 10 kΩ, with a 9,900–10,100 Ω interval.
Six-band example: use the same five bands, then a brown sixth band. Resistance remains 10 kΩ ±1%; the extra band indicates a TCR magnitude limit of 100 ppm/K under the selected chart convention. It does not add another zero or specify wattage.
A fractional example is green, blue, silver, gold: 56 × 0.01 = 0.56 Ω ±5%, giving 0.532–0.588 Ω. If selecting from optional resistor assortments (paid link), confirm the actual component specifications rather than assuming all bodies or band counts share a power rating.
Resistor color code chart and gray-band convention
- Black
- Digit 0 · multiplier ×1 · tolerance — · TCR 250 ppm/K
- Brown
- Digit 1 · multiplier ×10 · tolerance ±1% · TCR 100 ppm/K
- Red
- Digit 2 · multiplier ×100 · tolerance ±2% · TCR 50 ppm/K
- Orange
- Digit 3 · multiplier ×1,000 · tolerance ±0.05% · TCR 15 ppm/K
- Yellow
- Digit 4 · multiplier ×10,000 · tolerance ±0.02% · TCR 25 ppm/K
- Green
- Digit 5 · multiplier ×100,000 · tolerance ±0.5% · TCR 20 ppm/K
- Blue
- Digit 6 · multiplier ×1,000,000 · tolerance ±0.25% · TCR 10 ppm/K
- Violet
- Digit 7 · multiplier ×10,000,000 · tolerance ±0.1% · TCR 5 ppm/K
- Gray / grey
- Digit 8 · multiplier ×100,000,000 · tolerance ±0.01% · TCR 1 ppm/K
- White
- Digit 9 · multiplier ×1,000,000,000 · tolerance — · TCR —
- Gold
- Digit — · multiplier ×0.1 · tolerance ±5% · TCR —
- Silver
- Digit — · multiplier ×0.01 · tolerance ±10% · TCR —
- Pink
- Digit — · multiplier ×0.001 · tolerance — · TCR —
This implementation follows the values in IEC 60062:2016+A1:2019 Table 1, including pink ×0.001, orange ±0.05%, yellow ±0.02% and gray ±0.01%. Older charts and some manufacturer conventions show gray tolerance as ±0.05%. For a gray tolerance band or an unusual part, the actual manufacturer’s specification takes precedence. Do not silently treat the two gray tolerances as interchangeable.
The chart lists white as a digit and multiplier, but not a tolerance or TCR color. A missing tolerance band normally belongs to a three-band marking and is outside this tool’s 4/5/6-band modes. The tool does not claim that every mathematical combination is stocked by a supplier.
Accuracy, orientation and what the bands cannot tell you
Colors can look different with lighting, fading, heat damage and body coating. Read direction and band purpose must be identified before calculation. A first band, tolerance band and temperature band are not interchangeable. Special reliability or manufacturer markings may resemble an extra band, so verify unusual parts with their datasheet.
No wattage, maximum working voltage, surge rating, temperature class or suitability is inferred from the selected resistance. The result is not a claim that the part is undamaged. Use the existing Ohm’s Law Calculator for voltage/current relationships and the LED Resistor Calculator when choosing a resistor for a DC series LED string.
Optional solderless breadboards (paid link) can help arrange a compatible low-voltage prototype. Resistance, tolerance and TCR are only some of the component characteristics needed for a real design.
Resistor Color Code Calculator FAQs
Select two significant digit colors, then the multiplier and tolerance. Multiply the two-digit number by the color multiplier to get nominal ohms.
Five-band mode uses three significant digits before the multiplier and tolerance. The third digit is not a temperature band.
In this mode, the sixth band specifies temperature coefficient in ppm/K. It is reported separately from resistance and tolerance; it does not indicate wattage.
This calculator uses the IEC 60062:2016+A1:2019 value of gray ±0.01%. Some older or manufacturer charts use ±0.05%; identify the actual part convention from its datasheet.
No. You manually choose 4, 5 or 6 band colors. Image recognition, SMD codes, three-band parts, zero-ohm jumpers and special markings are outside scope.
No. The minimum and maximum use only the marked tolerance. Temperature, aging, meter uncertainty and operating conditions can produce additional differences.
Sources and methodology
Independent band-decoding implementation, reviewed October 24, 2026. Manufacturer datasheets control real component ratings. The linked organizations do not endorse this tool.