How Do You Read Resistor Color Codes?
Resistor color codes are a standard that marks a resistor's value with colored bands on its body. On a 4-band resistor, the first two bands are digits, the third is the multiplier (a power of 10), and the fourth is the tolerance. For example, brown-black-red-gold = 1, 0, ×100 = 1000 Ω (1 kΩ), 5% tolerance. Each color maps to a digit from 0 to 9.
Resistor color codes are a system that shows the value of classic (axial) resistors through the colored bands on them. By reading the colors you can find how many ohms the resistor is and its tolerance.
The Band Logic (4 and 5 Bands)
On the most common 4-band resistor: the first two bands are digits, the third band is the multiplier, and the fourth band is the tolerance. On 5-band ones, the first three bands are digits, the fourth is the multiplier and the fifth is the tolerance (more precise).
Color-Digit Table
| Color | Digit | Multiplier |
|---|---|---|
| Black | 0 | ×1 |
| Brown | 1 | ×10 |
| Red | 2 | ×100 |
| Orange | 3 | ×1,000 |
| Yellow | 4 | ×10,000 |
| Green | 5 | ×100,000 |
| Blue | 6 | ×1,000,000 |
| Gold | — | ±5% tolerance |
| Silver | — | ±10% tolerance |
Worked Example
A resistor with Brown – Black – Red – Gold bands: 1 (brown), 0 (black) → "10"; multiplier ×100 (red) → 10 × 100 = 1,000 Ω = 1 kΩ; tolerance ±5% (gold). So 1 kΩ ±5%.
SMD Resistor Code
On SMD resistors there's a number instead of colors: for example "472" = 47 × 10² = 4,700 Ω (4.7 kΩ). To verify the value you can measure it with a multimeter.
Common Mistakes
- Reading from the wrong end: start from the left, with the tolerance band (gold/silver) on the right.
- Confusing the multiplier with a digit: the third band (on a 4-band) is the multiplier, not a digit.
- Not distinguishing similar colors: brown and red can be confused on aged resistors; measure when in doubt.
Frequently Asked Questions
How do you read a 4-band resistor?+
Which digits do the colors represent?+
What does the tolerance band mean?+
Search parts related to "How Do You Read Resistor Color Codes?"
Find the right part by comparing price, stock and distributors.