Resistor Calculator decodes resistor color bands into a resistance value and back again, for 4-band, 5-band, and 6-band resistors.
Pick the band count, then set each color ring - or type a resistance value directly and the tool picks the closest matching bands for you. Click a ring on the drawing to jump straight to its selector.
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/°C |
| Red | 2 | ×100 | ±2% | 50 ppm/°C |
| Orange | 3 | ×1k | 15 ppm/°C | |
| Yellow | 4 | ×10k | 25 ppm/°C | |
| Green | 5 | ×100k | ±0.5% | |
| Blue | 6 | ×1M | ±0.25% | 10 ppm/°C |
| Violet | 7 | ×10M | ±0.1% | 5 ppm/°C |
| Gray | 8 | ×100M | ±0.05% | 1 ppm/°C |
| 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.