Resistor Color Code Decoder
Decode 3, 4, 5, and 6 band resistor color values instantly.
Updated
What is the Resistor Color Code Decoder?
Decode or encode color bands on through-hole resistors. Select the colors you see to read resistance, tolerance, and (for six-band parts) temperature coefficient. In encode mode, enter a value to see a representable band pattern.
Two modes:
- Decode – select 3, 4, 5, or 6 bands to read the resistance.
- Encode – enter a value such as
4.7k,1M, or0.22Ωand see a corresponding band pattern for the selected band count.
The tool uses common through-hole resistor color-band values. Encoding chooses bands that approximate the entered resistance at the selected band count; check the actual resistor specification before relying on the result.
How it works
Resistor color bands represent digits, multipliers, tolerance, and (on six-band resistors) temperature coefficient. The table below shows the values used by this tool.
| Colour | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | ×1 | – |
| Brown | 1 | ×10 | ±1% |
| Red | 2 | ×100 | ±2% |
| Orange | 3 | ×1 000 | – |
| Yellow | 4 | ×10 000 | – |
| Green | 5 | ×100 000 | ±0.5% |
| Blue | 6 | ×1 000 000 | ±0.25% |
| Violet | 7 | ×10 000 000 | ±0.1% |
| Grey | 8 | ×100 000 000 | ±0.05% |
| White | 9 | ×1 000 000 000 | – |
| Gold | – | ×0.1 | ±5% |
| Silver | – | ×0.01 | ±10% |
| None | – | – | ±20% |
How the decoder works
- Band count is determined – you select 3, 4, 5, or 6 bands.
- For decoding, the tool reads the first 2 or 3 bands as digits, the next band as the multiplier, and the final band(s) as tolerance and, if present, temperature coefficient.
- Example: Brown(1), Black(0), Red(×100), Gold(±5%) → 10×100 = 1 000 Ω → 1 kΩ ±5%.
- For encoding, enter a resistance value (e.g.
4.7k). The tool rounds it to a representable digit and multiplier combination for the selected band count, then chooses a tolerance color. The entered value may not be exactly representable. - Real‑time validation ensures only colours that make sense for a given band position are available – for instance, the multiplier band can never be black on a 6‑band resistor if the value is non‑zero.
The tool also supports six-band input, where the final band is interpreted as a temperature coefficient in ppm/°C. Check the component's datasheet when the value or tolerance matters.
Examples
Decode a 4‑band resistor
Select Brown, Black, Red, Gold to get 1 kΩ ±5%.
Bands: Brown, Black, Red, Gold1 kΩ ±5%Encode a 5‑band value
Enter “4.7k” with ±1% tolerance to see the matching 5-band color code.
4.7k, Tolerance 1%Colors: Yellow, Violet, Black, Brown, BrownDecode a 6‑band resistor
Read a precision resistor with temperature coefficient.
Violet, Green, Black, Orange, Brown, Brown750 kΩ ±1% 100 ppm/°CFrequently asked questions
What do the coloured bands on a resistor mean?
What do the coloured bands on a resistor mean?
Each colour represents a number, a multiplier, a tolerance, or (on 6‑band resistors) a temperature coefficient. For example, a 4‑band resistor with Brown‑Black‑Red‑Gold reads as 1 (brown), 0 (black), ×100 (red) = 1 000 Ω (1 kΩ) with a ±5% tolerance.
How do I read a 5‑band resistor?
How do I read a 5‑band resistor?
A 5‑band resistor has three significant digits, a multiplier, and a tolerance band. Example: Yellow‑Violet‑Black‑Orange‑Brown → 470 ×1 000 = 470 kΩ ±1%. Use the decoder’s 5‑band mode, pick the colours from left to right, and it calculates the value instantly.
Can I use this tool for 6‑band resistors?
Can I use this tool for 6‑band resistors?
Yes. The sixth band indicates the temperature coefficient (how much the resistance changes with temperature). Simply select 6‑band mode and choose all six colours. The tool will show the resistance, tolerance, and the temp coefficient in ppm/°C.
Why are some colours not available for certain band positions?
Why are some colours not available for certain band positions?
The color-band conventions restrict which colors can appear in some positions. For example, gold and silver are only valid as multipliers or tolerance bands – they never appear as significant digits. The decoder automatically filters the palette so you only see valid choices for each position, preventing impossible colour combinations.
How do I encode a resistance value to colours?
How do I encode a resistance value to colours?
Switch to Encode mode, type a value like 4.7k, 1M, or 4700, and choose the band count. The tool rounds the value to a representable digit-and-multiplier combination and selects a tolerance color. The bands may not reproduce the entered value exactly.
What does the tolerance colour mean?
What does the tolerance colour mean?
Tolerance tells you how much the actual resistance may deviate from the marked value.
- Gold = ±5%
- Silver = ±10%
- Brown = ±1%
- Red = ±2%
- Green = ±0.5%
- Blue = ±0.25%
- Violet = ±0.1%
- Grey = ±0.05% If no tolerance band is shown (3‑band or absent band), the default is ±20%.
Is my data safe? Does the tool send anything to a server?
Is my data safe? Does the tool send anything to a server?
The color selection and calculation are performed in your browser. Avoid entering private information; none is needed for this tool.
Does the decoder support SMD or surface‑mount resistors?
Does the decoder support SMD or surface‑mount resistors?
No – this tool is designed for traditional through‑hole axial resistors that use colour bands.
SMD resistors use numeric codes (like 103, 4R7) that are not covered here. We may add a separate decoder for those in the future.
Related tools
More utilities you might find handy.
Density Calculator
Calculate density, mass, or volume instantly with full unit conversion and material comparison
Frequency to Wavelength Converter
Convert wave frequency and wavelength using a selected or custom propagation speed.
Kinematic Equations Solver
Solve SUVAT kinematic motion equations for displacement, velocity, acceleration, and time.