Quick answer
Brown-black-red-gold is 1, 0, ×100 = 1,000 Ω (1 kΩ) ±5%, and yellow-violet-red is 4.7 kΩ. Read the bands from the side away from the gold or silver band.
How to use the Resistor Color Code Calculator
- Hold the resistor so the tolerance band (often gold or silver, and usually set slightly apart) is on the right.
- Choose 4, 5 or 6 bands, depending on how many color rings your resistor has.
- Select each band's color from left to right. The picture and value update instantly.
- To go the other way, open Value → colors and type a resistance such as 4.7 kΩ.
Example
A 4-band resistor shows yellow, violet, red, gold:
- Yellow = 4, violet = 7 →
47 - Red multiplier = ×100 →
4,700 Ω = 4.7 kΩ - Gold = ±5% → between 4,465 Ω and 4,935 Ω
The same 4.7 kΩ value on a precision 5-band resistor reads yellow, violet, black, brown, brown: 4-7-0 × 10 = 4,700 Ω, ±1%.
How it works
Resistors are too small to print numbers on, so their value is coded in colored rings:
- 4-band: two digits, a multiplier and a tolerance.
- 5-band: three digits, a multiplier and a tolerance (used for precision resistors).
- 6-band: like 5-band, plus a temperature coefficient that shows how much the value changes with temperature, in ppm per kelvin.
The value is the digits multiplied by the multiplier. The tolerance shows how far the real value may differ from the marked value.
Resistor color code chart
| Color | Digit | Multiplier | Tolerance | Temp. coefficient |
|---|---|---|---|---|
| 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% | ||
| None | ±20% |
A handy way to remember the digit order: Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Grey, White follows the rainbow in the middle, starting dark and ending light.
Most common resistor values and their colors
- 220 Ω: red, red, brown. A common LED resistor for 5 V circuits.
- 330 Ω: orange, orange, brown. Another popular LED value.
- 1 kΩ: brown, black, red. Used everywhere, from transistor bases to pull-ups.
- 10 kΩ: brown, black, orange. The classic pull-up and pull-down resistor for Arduino buttons.
- Can't tell the colors apart? Photograph the resistor in daylight and zoom in, or measure it with a multimeter set to the Ω range.
Frequently asked questions
Which side of a resistor do I read from?
Start from the end where the bands are closer to the edge. The tolerance band (gold, silver or brown on many resistors) is usually separated by a slightly larger gap and goes on the right. If it's unclear, measure the resistor with a multimeter.
What does a gold band mean?
As the last band, gold means ±5% tolerance. As the third band on a 4-band resistor, gold is a multiplier of ×0.1, used for values under 10 Ω.
How do I tell brown from red or orange?
Under warm or dim light these colors are hard to tell apart. Use bright white light, compare against a known resistor, or confirm with a multimeter.
Why does my value show “not exactly representable”?
Not every value can be shown with 2 or 3 significant digits. Standard resistor values come from the E-series (E12, E24, E96), so choose the nearest standard value.
What is the temperature coefficient?
The sixth band shows how much the resistance changes per degree of temperature, in parts per million per kelvin (ppm/K). For example, 100 ppm/K means a 0.01% change for each 1 °C.