The 47 ohm resistor colour code for a standard 4-band through-hole component is Yellow, Violet, Black, and Gold (for 5% tolerance) or Silver (for 10% tolerance). For a 5-band precision resistor, the sequence is Yellow, Violet, Black, Black, and Brown (1%) or Red (2%). In surface-mount (SMD) format, the marking is 470 (for 5%) or 47R0 (for 1%).
Whether you are pulling from a mixed bin or verifying a faded component on a legacy PCB, reading the bands correctly prevents circuit failures. Below is the definitive breakdown of the 47Ω value across all packaging standards, the specific traps that cause misreads, and a concrete decision matrix for selecting the right physical part for your build.
The Complete 47 Ohm Resistor Colour Code Reference
The table below maps the exact band colors and printed codes for a 47Ω resistance value across the three most common physical formats. Read through-hole resistors with the tolerance band (usually Gold, Silver, or Brown) on the right side.
| Format | Band 1 (Digit 1) | Band 2 (Digit 2) | Band 3 (Digit 3 / Multiplier) | Band 4 (Multiplier / Tolerance) | Band 5 (Tolerance) |
|---|---|---|---|---|---|
| 4-Band (5%) | Yellow (4) | Violet (7) | Black (×1) | Gold (±5%) | N/A |
| 4-Band (10%) | Yellow (4) | Violet (7) | Black (×1) | Silver (±10%) | N/A |
| 5-Band (1%) | Yellow (4) | Violet (7) | Black (0) | Black (×1) | Brown (±1%) |
| 5-Band (2%) | Yellow (4) | Violet (7) | Black (0) | Black (×1) | Red (±2%) |
SMD and Printed Code Variants
| SMD Package | Marking | Decoding Logic | Tolerance |
|---|---|---|---|
| 0805 / 0603 (Thick Film) | 470 | 47 × 10^0 (47 × 1) | ±5% |
| 0603 / 0402 (Precision) | 47R0 | 47.0Ω (R denotes decimal) | ±1% |
| 0201 (Micro SMD) | Blank | Too small for printing; requires reel label | ±1% or ±5% |
Regional and Standard Variants (IEC vs. EIA vs. BS)
Resistor markings are governed by international standards, but legacy boards and regional schematics often use alternative notations. Understanding these prevents confusion when cross-referencing a physical part with a schematic.
- IEC 60062 (Global Standard): This is the modern international standard that defines the color bands for through-hole resistors and the alphanumeric marking codes for SMDs. Under IEC 60062, the letter 'R' is used to indicate the decimal point for values under 1000Ω (e.g., 47R means 47.0Ω).
- EIA / MIL-PRF (US Military & Aerospace): While the color code itself aligns with IEC, US military spec sheets (like MIL-PRF-55342 for SMDs) often rely on strict 3-digit or 4-digit numeric codes and may use the EIA-96 system for 1% tolerances. However, because 47Ω is a standard E24 series value, it uses the standard '470' 3-digit code rather than the complex EIA-96 lookup table.
- Old UK / BS1852 (Legacy Schematics): Older British schematics and some European vintage audio gear use the BS1852 R-notation exclusively, dropping the ohm symbol (Ω) entirely. You will see 47R on the silkscreen or schematic. If you see R47, that means 0.47Ω, not 47Ω—a critical distinction in current-sense applications.
47R = 47 Ohms. 4R7 = 4.7 Ohms. R47 = 0.47 Ohms. The 'R' always replaces the decimal point.
Rows and Bands People Get Wrong (And How to Fix Them)
Misreading a 47Ω resistor usually happens because of manufacturing variances in the paint or confusion over the multiplier band. Here are the most common failure points on the bench.
1. The 'Black' Multiplier Trap (4-Band vs. 5-Band)
In a 4-band resistor, the third band is the multiplier. Black means ×10^0 (which is ×1). So, Yellow-Violet-Black = 47 × 1 = 47Ω.
In a 5-band resistor, the third band is the third significant digit, and the fourth band is the multiplier. To get 47Ω, the third digit must be 0 (Black), and the multiplier must be ×1 (also Black). This results in two consecutive black bands (Yellow-Violet-Black-Black). Beginners often read the second black band as a digit and calculate 470Ω instead of 47Ω. Always count the total number of bands on the body before assigning roles.
2. Faded Violet vs. Gray
Carbon film resistors subjected to high heat or prolonged UV exposure often suffer from pigment degradation. The Violet (7) band is notorious for fading to a washed-out gray or even a dirty brown. If your 47Ω resistor looks like Yellow-Gray-Black, you are likely looking at a faded 48Ω (which isn't a standard E12/E24 value anyway) or a misread 47Ω. Fix: Verify with a multimeter; 47Ω is a standard E24 value, whereas 48Ω is not.
3. Reading Backwards (The Tolerance Gap)
If you read Gold-Yellow-Violet-Black, you are holding the resistor backwards. Gold and Silver are never used as significant digit bands (the first band). Furthermore, manufacturers intentionally leave a wider physical gap between the multiplier band and the tolerance band. Always orient the resistor so the isolated tolerance band is on the far right.
Decision Path: Which 47Ω Resistor Should You Actually Buy?
Do not just buy 'a 47 ohm resistor'. The physical construction dictates noise, thermal stability, and power handling. Use this decision tree to select the exact part number for your project.
| Your Application | Required Spec | Concrete Part Recommendation |
|---|---|---|
| LED Current Limiting / Breadboarding | 1/4W, 5% Tolerance, Carbon Film | Yageo CFR-25JR-52-47R (Cheap, forgiving, standard axial leads) |
| Audio Signal Path / Op-Amp Feedback | 1/4W, 1% Tolerance, Metal Film (Low Noise, 50ppm/°C) | Vishay MRS25000C4709FCT00 (Tight tolerance, minimal thermal drift) |
| High-Power Snubber / Dummy Load | 2W to 5W, 5% Tolerance, Metal Oxide | Vishay PR02000204709JR500 (Flameproof, handles high transient heat) |
| Compact SMD PCB (Consumer Electronics) | 0805 Package, 1% Tolerance, Thick Film | Yageo RC0805FR-0747RL (Industry standard footprint, easy to hand-solder) |
Safe Interpretation When Markings Are Faded or Missing
When visual identification is impossible due to heat damage, conformal coating, or extreme fading, you must rely on electrical measurement. However, measuring a resistor while it is still soldered into a circuit will almost always yield a false, lower reading due to parallel resistance paths on the PCB.
The Definitive Measurement Protocol:
- De-energize and Isolate: Remove all power from the circuit. If measuring in-circuit, desolder at least one leg of the resistor to lift it off the pad, breaking the parallel circuit path.
- Zero Your Leads: Touch your multimeter probes together. Cheap test leads often have 0.2Ω to 0.5Ω of internal resistance. Note this value.
- Measure and Subtract: Place the probes across the resistor body. If your meter reads 47.3Ω and your lead resistance was 0.2Ω, the true resistance is 47.1Ω.
- Verify Tolerance: A reading of 44.6Ω to 49.4Ω confirms a 47Ω resistor with a 5% (Gold) tolerance band. A reading outside this window indicates either a damaged component (carbon film resistors typically drift high when stressed) or a misidentified value.
For further reading on standard component values and decoding, refer to the SparkFun Resistor Tutorial and the comprehensive All About Circuits color code reference.
