The standard resistor color code chart is governed by the IEC 60062 standard. For a standard 4-band axial resistor, the first two bands represent significant digits, the third band is the decimal multiplier, and the fourth band indicates tolerance. The universal color sequence is Black (0), Brown (1), Red (2), Orange (3), Yellow (4), Green (5), Blue (6), Violet (7), Grey (8), and White (9). Therefore, a 10kΩ resistor with a 5% tolerance is coded Brown, Black, Orange, Gold. If you are squinting at a component on a dimly lit workbench, remember that the tolerance band (usually Gold or Silver) is spaced slightly further apart from the others, giving you your starting orientation.
The Master IEC 60062 Resistor Color Code Chart
Before reading the table below, understand how the columns apply to your specific installation. The Digit and Multiplier columns apply to every through-hole resistor you will encounter. The Tolerance column applies to the final band on standard 4-band and 5-band resistors, dictating the maximum percentage deviation from the nominal value at room temperature (20°C). The Temperature Coefficient column only applies if you are using 6-band precision resistors in environments with high thermal fluctuation. Bookmark the quick-jump rows below for the most common values you will pull from your component bins.
| Color | Digit (1st/2nd/3rd Band) | Multiplier (Next Band) | Tolerance (Final Band) | Temp Coeff (6th Band ppm/°C) |
|---|---|---|---|---|
| Black | 0 | ×1 (10⁰) | — | 250 ppm/°C |
| Brown | 1 | ×10 (10¹) | ±1% (F) | 100 ppm/°C |
| Red | 2 | ×100 (10²) | ±2% (G) | 50 ppm/°C |
| Orange | 3 | ×1k (10³) | — | 15 ppm/°C |
| Yellow | 4 | ×10k (10⁴) | — | 25 ppm/°C |
| Green | 5 | ×100k (10⁵) | ±0.5% (D) | — |
| Blue | 6 | ×1M (10⁶) | ±0.25% (C) | 10 ppm/°C |
| Violet | 7 | ×10M (10⁷) | ±0.1% (B) | 5 ppm/°C |
| Grey | 8 | — | ±0.05% (A) | — |
| White | 9 | — | — | — |
| Gold | — | ×0.1 (10⁻¹) | ±5% (J) | — |
| Silver | — | ×0.01 (10⁻²) | ±10% (K) | — |
Reading the Bands and Applying Thermal Derating
Resistors come in three primary band configurations. A 4-band resistor uses two significant digits, one multiplier, and one tolerance band (e.g., Red, Violet, Red, Gold = 2,700Ω or 2.7kΩ at ±5%). A 5-band resistor adds a third significant digit for tighter 1% or 0.5% tolerances (e.g., Yellow, Violet, Black, Brown, Brown = 4,700Ω or 4.7kΩ at ±1%). A 6-band resistor is identical to the 5-band format but adds a temperature coefficient band at the far right.
How the Temperature Coefficient Modifies the Base Value
While wire ampacity tables use 'derating rows' based on insulation temperature ratings, the resistor color code chart uses the 6th band (Temperature Coefficient) as your thermal derating modifier. This value, measured in parts per million per degree Celsius (ppm/°C), tells you how much the base resistance shifts as the component heats up.
Worked Derating Example: Suppose you install a 10,000Ω (10kΩ) 6-band precision metal film resistor with a Brown temperature coefficient band (100 ppm/°C). The nominal value is calibrated at 20°C. If your PCB operates in an enclosure that reaches 70°C, the temperature rise (ΔT) is 50°C.
Calculation: 10,000Ω × (100 / 1,000,000) × 50°C = 50Ω.
Your 10kΩ resistor will derate (shift) to 10,050Ω under operating conditions. In a precision ADC voltage divider, this 0.5% shift can introduce measurable non-linearity, which is exactly why you specify a 10 ppm/°C (Blue band) resistor for metrology applications.
What the Color Code Chart Cannot Tell You
Relying solely on the color bands leaves critical engineering parameters undefined. The IEC 60062 chart dictates nominal resistance and tolerance, but it completely omits the following physical and electrical limits:
- Power Rating (Wattage): The chart cannot tell you if a resistor is rated for 1/8W, 1/4W, or 1/2W. Power rating is dictated by physical body size. A standard 0207 metric body (approx. 2.5mm diameter × 6.5mm length) is typically 1/4W. A 0309 body is 1/2W. Always measure the physical dimensions if the wattage is unknown.
- Power Derating Curves: A 1/4W resistor cannot dissipate 0.25W at all ambient temperatures. Standard MIL-PRF-55342 or Vishay professional thin-film derating curves dictate that power handling must be linearly derated to zero watts once the ambient temperature hits 155°C.
- Maximum Working Voltage: Even if Ohm's law suggests a 1MΩ 1/4W resistor can handle 500V (since P = V²/R), the physical gap between the internal helical cuts in the film cannot withstand that potential. Standard 1/4W resistors typically max out at 250V continuous working voltage.
- Parasitic Inductance and Capacitance: The chart does not indicate construction type. A wirewound resistor (often marked with a specific banding style or physically larger) will have high parasitic inductance, making it useless for RF or high-speed digital snubber circuits, whereas a metal film resistor will have minimal parasitics.
Frequently Asked Questions
How do I read a resistor color code chart if the bands are faded or burnt?
If a resistor has overheated, the brown and red bands often darken to a uniform black, and the body may blister. Do not trust the color chart in this scenario. Desolder one leg of the resistor to isolate it from the parallel paths of the circuit board, then measure it directly with a digital multimeter in resistance mode. If the measured value is more than 20% outside the expected tolerance band, the carbon or metal film has permanently degraded and the component must be replaced.
Which way do I read the resistor color bands to ensure correct orientation?
Always read from the band closest to the lead wire toward the center. The tolerance band (Gold, Silver, or sometimes a tight-tolerance color like Brown/Red on the far right) is typically spaced slightly further away from the other bands. If the spacing is identical on both sides, look for the multiplier band: it is highly unlikely to be Black or White. If you calculate a value in the gigohms or milliohms from one direction, flip the resistor and recalculate.
Why does my 5-band resistor color code chart calculation result in an invalid value?
The most common error with 5-band resistors is misidentifying the multiplier. Because 5-band resistors use three significant digits, the multiplier band is the fourth band, not the third. If you mistake the third digit for the multiplier, your calculated value will be off by orders of magnitude. Additionally, ensure you are not reading a 4-band resistor with a temperature coefficient band as a 5-band resistor; some older military-spec 4-band resistors include a 5th band indicating reliability/failure rate (e.g., a Yellow 5th band indicating 0.001% failure rate per 1,000 hours).
Are surface mount (SMD) resistors coded using the same color chart?
No. SMD resistors are too small for color bands and instead use printed numeric codes. Standard 5% SMD resistors use a 3-digit code (e.g., '103' = 10 × 10³ = 10kΩ), while 1% SMD resistors use a 4-digit code (e.g., '1002' = 100 × 10² = 10kΩ). Ultra-compact 0201 and 0402 size SMD resistors often have no marking at all, requiring you to track them carefully during the tape-and-reel or pick-and-place assembly process.
