The Complete 3-Band Resistor Color Code Reference Table
Read this table left-to-right. Band 1 is the tens digit, Band 2 is the ones digit, and Band 3 is the multiplier. Because there is no fourth band, the tolerance defaults to ±20%.
| Color | Band 1 (1st Digit) | Band 2 (2nd Digit) | Band 3 (Multiplier) | Multiplier Value | Example (B1-B2-B3) |
|---|---|---|---|---|---|
| Black | 0 | 0 | ×1 | 1Ω | Brown-Black-Black = 10Ω |
| Brown | 1 | 1 | ×10 | 10Ω | Red-Red-Brown = 220Ω |
| Red | 2 | 2 | ×100 | 100Ω | Yellow-Violet-Red = 4.7kΩ |
| Orange | 3 | 3 | ×1,000 (1k) | 1kΩ | Orange-Orange-Orange = 33kΩ |
| Yellow | 4 | 4 | ×10,000 (10k) | 10kΩ | Brown-Black-Yellow = 100kΩ |
| Green | 5 | 5 | ×100,000 (100k) | 100kΩ | Green-Blue-Green = 5.6MΩ |
| Blue | 6 | 6 | ×1,000,000 (1M) | 1MΩ | Blue-Grey-Blue = 68MΩ |
| Violet | 7 | 7 | ×10,000,000 | 10MΩ | — |
| Grey | 8 | 8 | ×100,000,000 | 100MΩ | — |
| White | 9 | 9 | ×1,000,000,000 | 1GΩ | — |
| Gold | — | — | ×0.1 | 0.1Ω | Red-Red-Gold = 2.2Ω |
| Silver | — | — | ×0.01 | 0.01Ω | Brown-Green-Silver = 0.15Ω |
Worked Example: You find a resistor with Yellow, Violet, and Orange bands. Yellow is 4, Violet is 7, and Orange is ×1,000. The value is 47 × 1,000 = 47,000Ω, or 47kΩ. Because it is a 3 band color code resistor, its actual value could legally sit anywhere between 37.6kΩ and 56.4kΩ (the ±20% tolerance window).
Standards, Variants, and the Legacy Body-Tip-Dot System
While electrical wiring colors vary wildly by region—such as the NEC guidelines in the US versus IEC 60446 in Europe and the old UK red/black phase colors—resistor color codes are globally unified under the IEC 60062 standard. If you are buying modern components, IEC 60062 applies universally regardless of your region.
However, if you are repairing vintage amplifiers, old radios, or mid-century test equipment, you must be aware of regional historical variants. Before axial color bands became the universal norm in the 1960s, many UK and European manufacturers used the body-tip-dot system.
Instead of three painted rings, the entire body of the resistor was painted the first digit color, the painted tip (or end cap) was the second digit, and a single dot of paint on the body was the multiplier. For example, a resistor with a Brown body (1), Black tip (0), and Red dot (×100) equals 1,000Ω (1kΩ). The tolerance was indicated by the physical background color of the component (e.g., a bare ceramic or beige background implied 20%).
Today, the 3-band format is largely obsolete for new designs. Modern logic circuits and precision analog designs require 5% (4-band) or 1% (5-band) tolerances. You will typically only encounter 3-band resistors in old carbon composition stock, cheap educational kits, or non-critical applications like basic LED current limiting where a 20% variance won't cause a failure.
Rows People Get Wrong and Safely Reading Faded Bands
Even experienced bench technicians misread 3 band color code resistors when dealing with specific edge cases or degraded components. Here are the most common traps and how to handle them.
The Multiplier Traps
- Black as a Multiplier (Band 3): Beginners often see Black and think "zero." If Band 3 is Black, the multiplier is ×1, not ×0. A Brown-Black-Black resistor is 10 × 1 = 10Ω. If the multiplier were zero, the resistor would have 0 ohms of resistance, which makes no physical sense.
- Gold and Silver Multipliers: While usually seen as tolerance bands (Band 4), Gold and Silver can appear as Band 3 on low-value resistors. Gold means ×0.1 and Silver means ×0.01. A Green-Blue-Gold resistor is 56 × 0.1 = 5.6Ω.
Faded and Heat-Damaged Bands
Carbon composition resistors (the primary type you will find with only three bands) are notorious for running hot and baking their own paint. Over decades, the phenolic resin body darkens, and the color bands fade. The most common misidentification is Red fading into Brown, or Orange fading into Red. This shifts your calculated value by a factor of 10.
Never guess a faded resistor's value in a high-voltage, precision timing, or current-sense circuit. A misread 100kΩ bleeder resistor as a 10kΩ can result in lethal shock hazards or catastrophic component failure. If the bands are ambiguous, desolder one leg of the resistor and measure it with a digital multimeter. Never measure resistance in-circuit, as parallel paths through transistors and capacitors will give you a falsely low reading.
For a deeper look at component degradation and measurement techniques, the All About Circuits resistor guide provides excellent bench-level troubleshooting advice for degraded carbon comps.
3-Band vs. 4-Band vs. 5-Band: Comparison Matrix
To understand where the 3 band color code resistor fits into the broader ecosystem, compare it against modern standard formats. This matrix helps you identify what you are holding and whether you need to swap it for a tighter-tolerance modern equivalent during a repair.
| Feature | 3-Band Resistor | 4-Band Resistor | 5-Band Resistor |
|---|---|---|---|
| Significant Digits | 2 | 2 | 3 |
| Multiplier Band | Band 3 | Band 3 | Band 4 |
| Tolerance Band | None (Implied ±20%) | Band 4 (Gold=5%, Silver=10%) | Band 5 (Brown=1%, Red=2%) |
| Typical Composition | Carbon Composition | Carbon Film / Thick Film | Metal Film / Precision Foil |
| Primary Use Case | Vintage repairs, non-critical pull-ups | General purpose DIY, hobbyist boards | Op-amp feedback, precision ADC dividers |
| Readability Over Time | Poor (paint fades with heat) | Good | Excellent |
When replacing a damaged 3-band resistor in a vintage circuit, you do not need to hunt down a modern 20% tolerance part. You can safely substitute a modern 5% (4-band) or 1% (5-band) metal film resistor of the same nominal value. The tighter tolerance will not harm the circuit; in fact, it will likely improve its thermal stability and noise floor. Just ensure you match the physical wattage rating (usually 1/2W or 1W for older carbon comps) and verify the voltage rating if working on tube amplifiers or CRT flyback circuits.
