A standard 4-band 150 ohm resistor has the color code Brown, Green, Brown, Gold (or Silver for 10% tolerance). A 5-band 150 ohm resistor uses Brown, Green, Black, Black, Gold. For surface mount devices (SMD), the standard E24 code is 151.
150 Ohm Resistor Color Code Reference Tables
The following tables provide the exact band configurations for 150 ohm resistors across different packaging styles, followed by the complete master chart used to decode any axial resistor.
Table 1: Specific 150 Ohm Configurations
| Format | Band 1 | Band 2 | Band 3 | Band 4 | Band 5 | Tolerance |
|---|---|---|---|---|---|---|
| 4-Band (Standard) | Brown (1) | Green (5) | Brown (x10) | Gold (±5%) | - | 5% |
| 4-Band (High Tol.) | Brown (1) | Green (5) | Brown (x10) | Silver (±10%) | - | 10% |
| 5-Band (Precision) | Brown (1) | Green (5) | Black (0) | Black (x1) | Gold (±5%) | 5% (or 1% if Brown) |
| SMD (0805/0603) | Printed Code: 151 (15 x 10^1) | 1% or 5% | ||||
Table 2: Complete IEC 60062 Master Color Chart
| Color | Significant Digit | Multiplier | Tolerance | Temperature Coeff (ppm/K) |
|---|---|---|---|---|
| Black | 0 | ×1 (10⁰) | - | - |
| Brown | 1 | ×10 (10¹) | ±1% (F) | 100 |
| Red | 2 | ×100 (10²) | ±2% (G) | 50 |
| Orange | 3 | ×1k (10³) | - | 15 |
| Yellow | 4 | ×10k (10⁴) | - | 25 |
| Green | 5 | ×100k (10⁵) | ±0.5% (D) | - |
| Blue | 6 | ×1M (10⁶) | ±0.25% (C) | 10 |
| Violet | 7 | ×10M (10⁷) | ±0.1% (B) | 5 |
| Grey | 8 | - | ±0.05% (A) | - |
| White | 9 | - | - | - |
| Gold | - | ×0.1 (10⁻¹) | ±5% (J) | - |
| Silver | - | ×0.01 (10⁻²) | ±10% (K) | - |
Standard Variants: IEC, Military, and Wiring Misconceptions
Unlike mains wiring—where North American NEC uses black/white/green, old UK uses red/black/green, and modern IEC uses brown/blue/green-yellow—resistor color codes do not vary by region. They are governed globally by a single standard: IEC 60062. Whether you buy a resistor in Tokyo, Berlin, or Chicago, the color-to-number mapping remains identical.
However, the application of the standard varies by component grade:
- Standard Commercial (IEC 60062): Uses 4 bands for 5% tolerance and 5 bands for 1% tolerance. This covers 95% of hobbyist and commercial PCBs.
- Military/Aerospace (MIL-PRF-55342): Often uses a strict 5-band system where the first three bands are significant digits, the fourth is the multiplier, and the fifth is a color-coded failure rate or tight tolerance (e.g., Brown for ±1%).
- Surface Mount (EIA-96): While standard 5% SMD resistors use a 3-digit code (like 151 for 150 ohms), high-precision 1% SMD resistors use the EIA-96 standard. In EIA-96, a three-character code like 22X is used (22 corresponds to 150 in the lookup table, X is the multiplier for 10⁰). Note that 150 ohms is a standard E24 value, so you will almost always see '151' rather than an EIA-96 code.
Never apply household wiring color logic to electronic components. A brown wire in a 240V IEC circuit is a live hot conductor, but a brown band on a resistor simply means the digit '1'. Mixing these domains is a common trap for beginners transitioning from home electrical to electronics bench work.
Rows and Bands People Get Wrong
When reading the master table above, specific rows and band positions consistently cause misreads on the bench. Here is how to avoid them:
The 'Brown vs. Red' Fading Problem
The Brown (1) and Red (2) rows are the most frequently confused, especially on older carbon composition resistors. When subjected to heat over decades, red pigment oxidizes and darkens, looking nearly identical to brown. If you are repairing vintage audio gear and suspect a 150 ohm (Brown-Green-Brown) might actually be a 250 ohm (Red-Green-Brown), do not trust your eyes. Carbon comp resistors also drift significantly with age; always verify with a meter.
The 'Black' Multiplier Confusion
In the table, the Black row serves as the digit '0', but as a multiplier, it means ×1 (10⁰). In a 5-band 150 ohm resistor (Brown-Green-Black-Black-Gold), the third band is Black (making the digits 1-5-0) and the fourth band is Black (meaning multiply by 1). Beginners often read the two black bands as '00' and mistakenly multiply by 100, calculating 15,000 ohms instead of 150.
Gold and Silver as Digits
Gold and Silver never appear in the Significant Digit column. They are exclusively multipliers (for values under 10 ohms) or tolerance indicators. If you see a gold band, it is either the multiplier (×0.1) or the final tolerance band (±5%). It is never a '1' or a '2'.
Safe Interpretation When Markings are Missing
If a resistor is burnt beyond recognition, the color code is destroyed. Never guess the value based on circuit position or physical size. To safely determine the required replacement:
- Trace the circuit schematic if available.
- If no schematic exists, carefully desolder at least one leg of the burnt resistor from the PCB.
- Measure the resistance across the component. If it reads open (OL), the internal element has fused, and you must rely on schematic analysis or peer community knowledge for that specific board revision.
- Crucial: Never measure a resistor while it is still soldered into the circuit. Parallel paths through ICs and other components will yield a falsely low reading, leading you to install the wrong replacement.
Frequently Asked Questions
What is the exact color code for a 150 ohm resistor?
For a standard through-hole 4-band resistor, the colors are Brown (1), Green (5), Brown (multiplier of 10), and Gold (5% tolerance). This calculates as 15 × 10 = 150 ohms. If you are using a 5-band precision resistor, the code is Brown (1), Green (5), Black (0), Black (multiplier of 1), and Gold or Brown (tolerance). This calculates as 150 × 1 = 150 ohms.
How do I read a 150 ohm resistor if the bands are faded or burnt?
Visual inspection is unreliable for faded or heat-damaged components. The only safe interpretation method is to use a digital multimeter set to the resistance (Ω) range. Desolder one leg of the resistor to isolate it from the rest of the circuit board, then place your probes across the leads. If the resistor is burnt open (reads 'OL' or infinite), you cannot measure it; you must consult the device's service manual or schematic to find the original specified value.
Is a 150 ohm 5-band resistor electrically different from a 4-band one?
The nominal resistance (150 ohms) is identical, but the precision and construction usually differ. A 4-band 150 ohm resistor typically has a 5% tolerance (meaning its actual value can range from 142.5Ω to 157.5Ω) and is often a cheaper carbon or thick metal film. A 5-band 150 ohm resistor usually indicates a 1% or 2% tolerance (actual value between 148.5Ω and 151.5Ω) and is typically a precision metal film. Always replace a 5-band precision resistor with another 5-band part in sensitive analog or measurement circuits.
What is the SMD code for a 150 ohm surface mount resistor?
For standard 5% tolerance SMD resistors (E24 series), the printed code is 151. The first two digits (15) are the significant figures, and the third digit (1) is the multiplier (10¹), giving 15 × 10 = 150 ohms. For 1% tolerance SMD resistors, you may occasionally see a 4-digit code like 1500 (150 × 10⁰ = 150 ohms) on larger packages like 1206, though '151' remains the most common marking across 0603 and 0805 sizes. For detailed SMD marking decoding, refer to manufacturer guides like the Vishay Resistor Color Code and SMD Marking Guide.
