Resistor Color Code Calculator
An interactive calculator to decode the value of a resistor from its color bands. Supports 4, 5, and 6-band resistors, and can find colors from a value.
How to Read Resistor Color Codes
Resistors are fundamental components in electronics, used to control current flow. Since they are often too small to print numbers on, a system of colored bands is used to indicate their resistance value. This calculator helps you decode that system instantly, but understanding the rules is a valuable skill for any electronics hobbyist or professional.
The Meaning of Each Band
Resistors can have 4, 5, or 6 bands. Here's what each band represents:
- For 4-Band Resistors: The first two bands represent the significant digits, the third is the multiplier (the power of 10), and the fourth is the tolerance.
- For 5-Band Resistors (High Precision): The first three bands are significant digits, the fourth is the multiplier, and the fifth is the tolerance.
- For 6-Band Resistors: Same as a 5-band, but with an extra sixth band representing the Temperature Coefficient, which indicates how much the resistance will change as its temperature changes.
Color Code Chart
| Color | Digit | Multiplier | Tolerance | Temp. Coeff. (ppm/K) |
|---|---|---|---|---|
| Black | 0 | 1 | - | 250 |
| Brown | 1 | 10 | ±1% | 100 |
| Red | 2 | 100 | ±2% | 50 |
| Orange | 3 | 1k | - | 15 |
| Yellow | 4 | 10k | - | 25 |
| Green | 5 | 100k | ±0.5% | 20 |
| Blue | 6 | 1M | ±0.25% | 10 |
| Violet | 7 | 10M | ±0.1% | 5 |
| Grey | 8 | 100M | ±0.05% | 1 |
| White | 9 | 1G | - | - |
| Gold | - | 0.1 | ±5% | - |
| Silver | - | 0.01 | ±10% | - |
A common mnemonic to remember the digit colors is: "Bad Boys Run Our Young Girls Behind Victory Garden Walls".
Related Electronics Calculators
Understanding resistors is just one part of electronics. To calculate the relationship between voltage, current, and resistance in a circuit, you'll need Ohm's Law. You can also use our Voltage Drop Calculator to determine energy loss over long wires. For other common conversions in science and engineering, check out our all-in-one Unit Converter.