Electronics
Resistor color code
4 color bands → resistance value in ohms and tolerance.
- Instant
- Free
- Private (processed locally)
- No sign-up
Decode a resistor
Select the colors of the 4 bands. The value in ohms, the tolerance and a resistor diagram appear instantly.
Principle
- Bands 1 and 2 = digits
- Band 3 = multiplier (×10ⁿ)
- Band 4 = tolerance (±%)
- Value = (10·d1 + d2) × 10^mult
Example
| Bands | Value |
|---|---|
| Brown, black, red, gold | 1 kΩ ±5% |
| Calculation | 10 × 100 = 1000 Ω |
100% local calculation, no data sent.
Frequently asked questions
How do I read a color code?
The first two bands give the digits, the third the multiplier (power of 10), the fourth the tolerance.
What are the color values?
Black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. Gold and silver are multiplier/tolerance.
How do I compute the resistance?
Value = (digit1 × 10 + digit2) × 10^multiplier. E.g. brown-black-red = 10 × 100 = 1000 Ω = 1 kΩ.
What about 5-band resistors?
This tool handles the 4-band code, the most common. 5-band parts add a third significant digit.