How to Read Resistor Color Codes
Resistors are marked with colored bands that represent their value, tolerance, and sometimes temperature coefficient. The system is standardized and works for 3-band, 4-band, 5-band, and 6-band resistors.
Basic Rules
- 3 bands: two digits + multiplier. Tolerance is 20% (no band).
- 4 bands: two digits + multiplier + tolerance.
- 5 bands: three digits + multiplier + tolerance (used for 1% or 2% precision resistors).
- 6 bands: like 5 bands, with an extra band for temperature coefficient or reliability.
Resistor Color Code Table
| Color | Digit | Multiplier | Tolerance | Temp. Coefficient |
|---|---|---|---|---|
| Black | 0 | ×1 | ||
| Brown | 1 | ×10 | ±1% | 100 ppm/K |
| Red | 2 | ×100 | ±2% | 50 ppm/K |
| Orange | 3 | ×1k | 15 ppm/K | |
| Yellow | 4 | ×10k | 25 ppm/K | |
| Green | 5 | ×100k | ±0.5% | |
| Blue | 6 | ×1M | ±0.25% | |
| Violet | 7 | ×10M | ±0.1% | |
| Gray | 8 | ×100M | ±0.05% | |
| White | 9 | ×1G | ||
| Gold | ×0.1 | ±5% | ||
| Silver | ×0.01 | ±10% | ||
| None | ±20% |
Examples
- 3-band: Red, Red, Brown → 220 Ω ±20%
- 4-band: Green, Blue, Red, Gold → 5.6 kΩ ±5%
- 5-band: Red, Yellow, Orange, Black, Brown → 243 Ω ±1%
- 6-band: Red, Red, Brown, Brown, Brown, Red → 2.21 kΩ ±1%, 50 ppm/°C
Standard Resistor Series (E-Series)
Commercial resistors are produced in preferred value series defined by the IEC. Each series covers one decade (10 Ω–100 Ω, 100 Ω–1 kΩ, etc.) with values spaced according to the tolerance.
| Series | Tolerance | Values per Decade | Example Values |
|---|---|---|---|
| E6 | ±20% | 6 | 10, 15, 22, 33, 47, 68 |
| E12 | ±10% | 12 | 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 |
| E24 | ±5% | 24 | 10, 11, 12, 13, 15, 16, 18, 20, … 91 |
| E48 | ±2% | 48 | 100, 105, 110, 115, … 953 |
| E96 | ±1% | 96 | 100, 102, 105, 107, … 976 |
| E192 | ±0.5% or better | 192 | 100, 101, 102, 104, … 988 |
FAQs
I have a 6-band resistor. How do I read it?
Enter the first five colors as digits and multiplier. The sixth band gives either the reliability (failure rate) or the temperature coefficient.
My resistor has only 3 bands
That means it is a 20% tolerance resistor. Only two digits and a multiplier are shown; tolerance is assumed to be ±20%.
Which side is the first band?
Bands are usually grouped on one side of the resistor. Hold the resistor with the grouped bands to the left. Tolerance bands (gold or silver) are always on the right. The first band is never gold or silver.
About the Resistor Calculator
Resistors are among the most widely used components in electronics. This calculator provides a practical way to determine resistor values, decode resistor color codes, and calculate the result of series or parallel connections. Instead of searching through charts or doing manual calculations, you can obtain precise results directly here.
Features
- Resistor value calculator: Check or confirm resistance values.
- Color code calculator: Translate resistor color bands into numeric values.
- Series and parallel calculator: Compute equivalent resistance for combined resistors.