How to read resistor color codes
Through-hole resistors are too small to print a value on, so they carry colored bands instead. Each color stands for a number, and the position of the band tells you whether that number is a digit, a multiplier, a tolerance or a temperature coefficient.
Which end do I start from?
Hold the resistor so the bands are bunched toward the left. The tolerance band is usually gold or silver, sits slightly apart from the others, and goes on the right. Read left to right. If you are unsure, try both directions: only one usually gives a standard value, which this calculator flags with an “E12” or “E24” badge.
4, 5 and 6 band resistors
- 4 band: two digits, a multiplier and a tolerance. Common on ±5% carbon film resistors.
- 5 band: three digits, a multiplier and a tolerance. Used on ±1% and tighter metal film resistors where the extra digit matters.
- 6 band: the same as 5 band plus a final band for the temperature coefficient, which says how much the resistance drifts per degree of temperature change, in parts per million per kelvin (ppm/K).
Color chart
| Color | Digit | Multiplier | Tolerance | Temp. coeff. |
|---|---|---|---|---|
| Black | 0 | ×1 | — | 250 ppm/K |
| 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% | 20 ppm/K |
| Blue | 6 | ×1M | ±0.25% | 10 ppm/K |
| Violet | 7 | ×10M | ±0.1% | 5 ppm/K |
| Grey | 8 | ×100M | ±0.05% | 1 ppm/K |
| White | 9 | ×1G | — | — |
| Gold | — | ×0.1 | ±5% | — |
| Silver | — | ×0.01 | ±10% | — |
A resistor with no tolerance band at all is ±20%.
A worked example
Yellow, violet, red, gold: yellow is 4 and violet is 7, giving 47. Red is a ×100 multiplier, so the value is 4,700 Ω, or 4.7 kΩ. Gold means ±5%, so the real resistance can be anywhere from 4.465 kΩ to 4.935 kΩ.
Standard values
Resistors are made in preferred value series rather than every possible number. The E12 series (10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82) covers most hobby parts, and E24 adds values in between. Precision parts use E48, E96 or E192. When you type a value into the box above, the calculator picks the closest value the selected number of bands can represent.
