How to read a resistor colour code
- Choose Colours to value and the number of bands on your resistor: 4, 5 or 6.
- Pick the colour of each band from left to right, starting at the end away from the gold or silver band. You can also click a band on the drawing.
- Read the resistance, tolerance and range. To go the other way, choose Value to colours and type a value like 4.7k, 4k7 or 220.
The colour code
The colours and their meanings follow IEC 60062.
| Colour | 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% | 10 ppm/K |
| Violet | 7 | × 10M | ±0.1% | 5 ppm/K |
| Grey | 8 | × 100M | ||
| White | 9 | × 1G | ||
| Gold | × 0.1 | ±5% | ||
| Silver | × 0.01 | ±10% | ||
| None | ±20% |
Charts disagree about a few rare precision codes, such as grey, orange and yellow as tolerance bands, so the calculator offers only the tolerance and tempco colours that every chart agrees on. If a part uses something else, its datasheet will say.
Typing a value
In Value to colours mode you can type values the way they’re printed on schematics: 4.7k and 4k7 both mean 4,700 Ω, R47 means 0.47 Ω and 2M2 means 2.2 MΩ. A 4-band code holds two significant digits and a 5 or 6-band code holds three; if your value needs more, the calculator rounds it and tells you. To work out the current or power through a resistor, use the Ohm’s law calculator.