To read a standard 4-band resistor, read the first two bands as significant digits, the third band as the multiplier (number of zeros to add), and the fourth band as the tolerance. For a 5-band resistor, the first three bands are significant digits, the fourth is the multiplier, and the fifth is tolerance. A 6-band resistor adds a temperature coefficient band at the end. Always read from the band closest to the edge toward the center, leaving the wider-spaced tolerance band on the right.
The Complete Resistor Color Code Reference Table
The table below maps every standard color to its corresponding digit, multiplier, tolerance, and temperature coefficient (TCR) values according to the IEC 60062 standard. Keep this chart at your bench for immediate reference.
| Color | Digit (1st/2nd/3rd Band) | Multiplier (4th/3rd Band) | Tolerance (5th/4th Band) | Temp. Coeff. (6th Band) |
|---|---|---|---|---|
| Black | 0 | ×1 (10⁰) | — | 250 ppm/°C |
| Brown | 1 | ×10 (10¹) | ±1% | 100 ppm/°C |
| Red | 2 | ×100 (10²) | ±2% | 50 ppm/°C |
| Orange | 3 | ×1,000 (10³) | — | 15 ppm/°C |
| Yellow | 4 | ×10,000 (10⁴) | — | 25 ppm/°C |
| Green | 5 | ×100,000 (10⁵) | ±0.5% | 20 ppm/°C |
| Blue | 6 | ×1,000,000 (10⁶) | ±0.25% | 10 ppm/°C |
| Violet | 7 | ×10,000,000 (10⁷) | ±0.1% | 5 ppm/°C |
| Gray | 8 | ×100,000,000 (10⁸) | ±0.05% | 1 ppm/°C |
| White | 9 | ×1,000,000,000 (10⁹) | — | — |
| Gold | — | ×0.1 (10⁻¹) | ±5% | — |
| Silver | — | ×0.01 (10⁻²) | ±10% | — |
Decoding 4-Band, 5-Band, and 6-Band Resistors
Understanding what each row means in practice requires knowing which resistor construction you are holding. The physical band count dictates the precision of the component.
4-Band Resistors (Carbon Film / General Purpose):
These are your standard 5% or 10% tolerance workhorses. Let's decode a resistor with Brown-Black-Red-Gold bands. Brown is 1, Black is 0. The first two digits are '10'. The Red multiplier means ×100. Therefore, 10 × 100 = 1,000 ohms (1kΩ). The Gold band indicates a ±5% tolerance, meaning the actual resistance can fall anywhere between 950Ω and 1,050Ω.
5-Band Resistors (Metal Film / Precision):
Used when you need 1%, 0.5%, or tighter tolerances, such as in analog-to-digital converter (ADC) voltage dividers. Consider a Brown-Black-Black-Brown-Brown resistor. The first three digits are 1-0-0 (100). The fourth band (Brown) is a ×10 multiplier. 100 × 10 = 1,000 ohms (1kΩ). The final Brown band dictates a tight ±1% tolerance (990Ω to 1,010Ω). As noted in All About Circuits, metal film resistors also generate significantly less thermal noise than carbon film, making the 5-band variant mandatory for audio preamp circuits.
6-Band Resistors (High-Stability / Instrumentation):
The sixth band indicates the Temperature Coefficient of Resistance (TCR), measured in parts per million per degree Celsius (ppm/°C). A 6-band resistor with a 50 ppm/°C (Red) TCR will drift by a maximum of 0.005% for every 1°C change in ambient temperature. This is critical for outdoor telemetry or high-power environments where the board temperature fluctuates wildly.
Rows People Get Wrong (and Faded Band Fixes)
Visual misidentification is the leading cause of bench errors when reading color codes. Here are the specific traps and how to avoid them.
Never trust a multimeter reading on a resistor while it is still soldered into a PCB. Parallel circuit paths (like bypass capacitors or IC pins) will create alternative routes for the meter's test current, yielding a falsely low resistance reading. If a resistor reads 2.4kΩ in-circuit but the color bands say 10kΩ, the resistor is likely fine, but the surrounding circuit is pulling the reading down. Always desolder and lift at least one leg before measuring.
Red vs. Orange Confusion:
Under 4000K LED shop lights, a heat-faded red 1/4W carbon film resistor looks almost identical to orange. If you misread a Red-Red-Brown (220Ω) LED current limiter as Orange-Orange-Brown (330Ω), your LED current drops by 33%, resulting in noticeable dimming. Always verify suspect red/orange bands with a meter.
Violet vs. Gray Lighting Shifts:
Violet (7) and Gray (8) are notoriously difficult to distinguish in low-light conditions or on resistors with a thick, glossy epoxy coating. Violet often reflects light with a bluish tint, while gray appears flat. If you are building a precision DAC ladder, do not rely on visual sorting; meter every 5-band resistor before soldering.
The Multiplier vs. Tolerance Spacing Trick:
Gold and Silver serve double duty: they can be multipliers (×0.1 or ×0.01) or tolerance bands (±5% or ±10%). The physical spacing is your only visual cue. The tolerance band is always printed slightly further away from the main cluster of value bands, and it is often slightly thicker. If the spacing is uniform, look for the metallic sheen of the gold/silver band at the extreme edge of the component body.
Regional Standards and Legacy Markings
While the color code is globally recognized, the governing standards and legacy variants differ by region and era.
Modern Global Standard (IEC 60062):
The International Electrotechnical Commission (IEC) standard 60062 is the current universal authority for resistor and capacitor marking codes. If you are buying modern components from distributors like Digi-Key or Mouser, they strictly adhere to IEC 60062 color mappings. For a deep dive into component standards, SparkFun's Resistor Tutorial provides an excellent breakdown of how these IEC standards translate to modern manufacturing.
Legacy British Standard (BS1852) and Letter Codes:
Older UK equipment and some military-spec (MIL-R-22684) resistors occasionally used different body colors to denote wattage or relied on the BS1852 alphanumeric system instead of full color bands. You will still see BS1852 legacy formats printed on modern surface-mount and some axial resistors. Instead of a decimal point, which can be rubbed off or misprinted, they use the multiplier letter as the decimal. For example, 4K7 means 4.7kΩ, and R22 means 0.22Ω.
Old UK / Pre-1970s Dot Systems:
Vintage radios and early amplifiers sometimes used the "body-tip-dot" system. The body color was the first digit, the colored tip was the second digit, and a painted dot on the side was the multiplier. Tolerance was assumed to be ±20% unless a specific colored band was present at the base. When restoring vintage gear, always cross-reference the schematic rather than trusting these archaic dot markings, as heat and UV exposure severely degrade the original body pigments.
Decision Path: Picking the Right Replacement Resistor
When a resistor fails or you are designing a new circuit, do not just grab any component that matches the ohm value. Use this decision matrix to select the exact band count, tolerance, and concrete part series for your application.
| Application Scenario | Required Band Count | Tolerance & TCR | Concrete Part Pick (1kΩ Example) |
|---|---|---|---|
| General DIY / LED Dropping / Breadboarding Low cost, non-critical timing or voltage. |
4-Band | ±5% (Gold) Standard TCR |
Yageo CFR-25JT-52-1K (1/4W Carbon Film, 5%) |
| Precision Audio / ADC / Sensor Bridges Requires low thermal noise and tight voltage accuracy. |
5-Band | ±1% (Brown) ±50 ppm/°C |
Vishay CMF551K0000FKEB (1/2W Metal Film, 1%, 100ppm) |
| High-Temp Industrial / Automotive Telemetry Must maintain value across -40°C to +125°C swings. |
6-Band | ±0.1% (Violet) ±15 ppm/°C (Orange) |
TE Connectivity H41K00BZA (1/2W Precision Metal, 0.1%) |
If you are repairing a vintage audio amplifier and need to replace a noisy carbon composition resistor, deliberately choose a 4-band carbon film replacement (like the Yageo CFR series) rather than a 5-band metal film, as the slight thermal noise profile of carbon better matches the original circuit's noise floor expectations in high-impedance tube grids. For all modern microcontroller and sensor applications, default to the Vishay CMF metal film series; the 1% tolerance and low noise floor justify the negligible price increase over standard carbon parts.
