Resistor Colour Code Calculator
Instantly decode 4, 5, and 6-band resistor colour codes to find the exact resistance value, tolerance, and temperature coefficient.
Calculate Resistance Value
Select the number of bands on your resistor and choose the corresponding colours to instantly decode its electrical properties.
Resistor Decoder
Enter the colour bands from left to right (tolerance band is usually spaced further apart).
How it Works
Understanding resistor bands
Significant Digits
The first 2 (or 3 for 5/6-band) colours represent the core numerical digits of the resistance value.
Multiplier
The next band tells you what power of 10 to multiply the significant digits by (e.g., Red = ×100).
Tolerance
This band indicates the manufacturing precision. Gold means the actual value is within ±5% of the stated value.
Temperature Coefficient
Exclusive to 6-band resistors, this shows how much the resistance changes per degree Kelvin (ppm/K).
Standard Colour Code Chart
A quick reference table for decoding resistor colour bands according to the international IEC 60062 standard.
| Colour | Digit | Multiplier | Tolerance | Temp. Coeff. (ppm/K) |
|---|---|---|---|---|
| Black | 0 | ×1 Ω | – | – |
| Brown | 1 | ×10 Ω | ±1% | 100 |
| Red | 2 | ×100 Ω | ±2% | 50 |
| Orange | 3 | ×1 kΩ | – | 15 |
| Yellow | 4 | ×10 kΩ | – | 25 |
| Green | 5 | ×100 kΩ | ±0.5% | – |
| Blue | 6 | ×1 MΩ | ±0.25% | 10 |
| Violet | 7 | ×10 MΩ | ±0.1% | 5 |
| Grey | 8 | ×100 MΩ | ±0.05% | 1 |
| White | 9 | ×1 GΩ | – | – |
| Gold | – | ×0.1 Ω | ±5% | – |
| Silver | – | ×0.01 Ω | ±10% | – |
| None | – | – | ±20% | – |
Resistor Code FAQ
Answers to the most frequently asked questions about reading and calculating resistor colour codes.
For a 4-band resistor, the first two bands represent the significant digits, the third band is the multiplier (number of zeros to add), and the fourth band indicates the tolerance (accuracy) of the resistor. Always read from the end where the bands are closest together.
A 5-band resistor has three significant digit bands, one multiplier band, and one tolerance band, offering higher precision than a 4-band resistor. A 6-band resistor adds a sixth band that indicates the temperature coefficient (ppm/K), showing how much the resistance changes with temperature variations.
Gold and silver bands are typically used for the multiplier or tolerance bands. As a tolerance, gold means ±5% and silver means ±10%. As a multiplier, gold means multiply the base value by 0.1, and silver means multiply by 0.01.
Always start reading from the end where the bands are closest together. The tolerance band (usually gold or silver) is typically spaced slightly further apart from the other bands and should be read last, positioned on the right-hand side.