A 5 band resistance color code uses the first three bands for significant digits, the fourth band for the multiplier, and the fifth band for tolerance. This format is the global standard for precision 1% and 2% tolerance metal film resistors (such as the ubiquitous RN55, RN60, or MF1/4W series). Unlike 4-band resistors which only offer two significant digits, the 5-band system allows you to read values like 4.72kΩ directly off the component body without guessing.
The Complete 5-Band Resistor Reference Table (IEC 60062)
The following table maps every color to its corresponding value across all five bands. This data is governed globally by the IEC 60062 standard. Keep this bookmarked for your bench.
| Color | Band 1 (1st Digit) | Band 2 (2nd Digit) | Band 3 (3rd Digit) | Band 4 (Multiplier) | Band 5 (Tolerance) |
|---|---|---|---|---|---|
| Black | 0 | 0 | 0 | ×1 (10⁰) | — |
| Brown | 1 | 1 | 1 | ×10 (10¹) | ±1% (F) |
| Red | 2 | 2 | 2 | ×100 (10²) | ±2% (G) |
| Orange | 3 | 3 | 3 | ×1k (10³) | — |
| Yellow | 4 | 4 | 4 | ×10k (10⁴) | — |
| Green | 5 | 5 | 5 | ×100k (10⁵) | ±0.5% (D) |
| Blue | 6 | 6 | 6 | ×1M (10⁶) | ±0.25% (C) |
| Violet | 7 | 7 | 7 | ×10M (10⁷) | ±0.1% (B) |
| Gray | 8 | 8 | 8 | — | ±0.05% (A) |
| White | 9 | 9 | 9 | — | — |
| Gold | — | — | — | ×0.1 (10⁻¹) | ±5% (J) |
| Silver | — | — | — | ×0.01 (10⁻²) | ±10% (K) |
Decoding the Bands and Calculating Values in Practice
To read a 5-band resistor, you must first identify the reading direction. The tolerance band (Band 5) is almost always Gold, Silver, or Brown, and is typically separated from the other four bands by a slightly wider physical gap on the epoxy body. Always read from the end opposite the tolerance band.
Worked Numeric Example
Let's decode a resistor with the following bands from left to right: Brown - Black - Black - Red - Brown.
- Band 1 (Brown): 1
- Band 2 (Black): 0
- Band 3 (Black): 0
- Band 4 (Red): ×100 (Multiplier)
- Band 5 (Brown): ±1% (Tolerance)
Calculation: 100 × 100 = 10,000 ohms. This is a 10kΩ resistor with a 1% tolerance. In practice, this means the actual measured resistance will fall between 9,900Ω and 10,100Ω at room temperature (20°C).
The 'Rows People Get Wrong' and Faded Band Recovery
Even experienced engineers misread color codes under poor lighting or when components have been thermally stressed. Here are the specific rows and scenarios that cause the most mistakes on the bench.
Common Color Confusions
- Red (2) vs. Orange (3): When a resistor overheats, the epoxy body darkens. A red band will often bake into a dark orange hue. If you suspect thermal stress, do not trust the color; measure it.
- Green (5) vs. Blue (6): Under warm 3000K LED bench lighting, dark green and dark blue look nearly identical. Switch to a 5000K daylight lamp or take the component to a window with natural light.
- Black Multiplier (×1) vs. Brown Multiplier (×10): This is a one-order-of-magnitude error. A 100Ω resistor (Brown-Black-Black-Black) misread as Brown-Black-Black-Brown becomes a 1kΩ resistor. This mistake routinely destroys LED driver circuits and bias networks.
Safe Interpretation When Markings are Faded or Missing
If the 5th band is completely burned off or the paint has chipped away, never guess the tolerance for a precision circuit. Assume the worst-case scenario (±5% or worse) for your circuit simulations. To recover the exact value:
- Clean the body with isopropyl alcohol (IPA) to remove flux residue that might be obscuring the bands.
- Use a digital multimeter (DMM). For 1% resistors under 100Ω, use a 4-wire Kelvin measurement if your meter supports it, or subtract your test lead resistance (usually 0.2Ω to 0.4Ω) from the final reading.
- If the multiplier band is entirely missing, read the first three digits, then use your DMM to determine the order of magnitude (e.g., if digits are 4-7-0 and the meter reads ~4.7kΩ, your multiplier was Orange).
Component Standards vs. Mains Wire Codes (IEC vs. NEC vs. Old UK)
A critical safety note for makers building mains-powered projects: do not conflate component color codes with electrical wiring color codes. While your 5-band resistor follows the global IEC 60062 standard, the wires connecting your power supply to the mains follow entirely different regional codes. Mixing these up can result in lethal shock hazards or short circuits.
For example, a Green band on a resistor means the digit '5'. But a Green wire in a US NEC-compliant mains cable is the Equipment Ground. A Brown band on a resistor means '1', but a Brown wire in an IEC-compliant European appliance cord is the live Line voltage.
| Wire Color | US (NEC Article 200/210) | EU / Global (IEC 60446) | Old UK (Pre-2006) | Resistor Band (IEC 60062) |
|---|---|---|---|---|
| Brown | Phase 2 (or Line in some DC) | Line (Live) | Line (Live) | Digit 1 / ×10 |
| Blue | Phase 3 (or High-Leg) | Neutral | Neutral | Digit 6 / ×1M |
| Green / Green-Yellow | Equipment Ground | Protective Earth | Earth | Digit 5 / ×100k |
| Black | Line (Live) / Hot | Line 2 (3-phase) | Line 2 (3-phase) | Digit 0 / ×1 |
| White / Gray | Neutral | — | — | Digit 9 / — |
Always verify your region's wiring standards via the National Fire Protection Association (NFPA) if you are in the US, or the International Electrotechnical Commission (IEC) if you are in Europe/elsewhere. When wiring a DIY bench power supply, use heat-shrink tubing or colored electrical tape to explicitly mark your mains wires according to your local code, regardless of what colors the internal IEC power cord happens to use.
By keeping your IEC 60062 component reading strictly separated from your NEC/IEC wiring practices, you ensure both accurate circuit behavior and personal safety on the bench.
