To read a resistance color code, identify the tolerance band (usually gold or silver) on the right, then read the remaining bands left-to-right using the IEC 60062 standard chart. The first bands represent significant digits, the next is the multiplier, and the final band is the tolerance. Unlike electrical wire color codes—which vary drastically between US NEC, EU IEC, and old UK standards—resistor color bands are universally standardized globally. There is no regional guessing required; a 4.7kΩ resistor reads the same in Tokyo as it does in Texas.
The Master IEC 60062 Resistor Color Code Table
The following table is your bench reference for through-hole resistors. Memorize the sequence (Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White) as it maps directly to the digits 0 through 9.
| Color | Digit (1st, 2nd, 3rd) | Multiplier (10^x) | Tolerance |
|---|---|---|---|
| Black | 0 | ×1 (10⁰) | — |
| Brown | 1 | ×10 (10¹) | ±1% (F) |
| Red | 2 | ×100 (10²) | ±2% (G) |
| Orange | 3 | ×1k (10³) | — |
| Yellow | 4 | ×10k (10⁴) | — |
| Green | 5 | ×100k (10⁵) | ±0.5% (D) |
| Blue | 6 | ×1M (10⁶) | ±0.25% (C) |
| Violet | 7 | ×10M (10⁷) | ±0.1% (B) |
| Gray | 8 | ×100M (10⁸) | ±0.05% (A) |
| White | 9 | ×1G (10⁹) | — |
| Gold | — | ×0.1 (10⁻¹) | ±5% (J) |
| Silver | — | ×0.01 (10⁻²) | ±10% (K) |
Standard Variants: 4-Band, 5-Band, and SMD
Note on Regional Standards: While wire colors have strict regional variants (NEC vs IEC vs old UK), resistor color codes do not. They are universally governed by IEC 60062. However, component formats vary by manufacturing standard and precision tier. Here is how to identify which standard applies to the physical part in your hand.
| Format | Band Count / Markings | Typical Use Case | How to Read |
|---|---|---|---|
| 4-Band (Carbon Film) | 4 colored bands | General purpose, pull-ups, LED current limiting (±5% tolerance). | Band 1 & 2 = Digits. Band 3 = Multiplier. Band 4 = Tolerance. |
| 5-Band (Metal Film) | 5 colored bands | Precision analog circuits, feedback loops, audio (±1% or better). | Band 1, 2 & 3 = Digits. Band 4 = Multiplier. Band 5 = Tolerance. |
| 6-Band (Precision) | 6 colored bands | High-reliability or temperature-sensitive environments. | Same as 5-band, but Band 6 indicates Temperature Coefficient (ppm/°C). |
| SMD (EIA-96 / 3-digit) | Printed numbers (e.g., 103, 4702) | Surface mount PCBs, high-density modern electronics. | First digits are significant figures, last digit is the multiplier (number of zeros). |
The "Rows People Get Wrong" Trap
Even experienced technicians misread resistors when rushing. These are the most common failure points when interpreting the IEC 60062 chart:
- Gold and Silver as the First Digit: Gold and Silver are never used as the first significant digit. If you see Gold or Silver on the far left, you are holding the resistor backward. Flip it.
- Black as a Multiplier: Black as a digit is 0. But Black as a multiplier means ×1 (10⁰). A resistor with Yellow, Violet, Black, Gold is 47 × 1 = 47Ω, not 470Ω or 0Ω.
- The "Red vs Brown" Lighting Illusion: Under fluorescent or cool-white LED bench lights, dark brown often looks red. If your calculated value yields a non-standard E12/E24 series number (e.g., 21kΩ instead of 22kΩ), you likely misread a brown band as red. Check the Sparkfun resistor guide for standard E-series values to sanity-check your math.
- SMD "103" vs "1003": On SMD resistors, "103" means 10 × 10³ = 10kΩ. But "1003" (4-digit code) means 100 × 10³ = 100kΩ. Count the total digits before calculating.
Decision Path: Identifying and Reading Your Resistor
Use this decision tree to terminate your identification process with a concrete value or action.
| Condition (If...) | Observation (Then...) | Concrete Action / Result |
|---|---|---|
| Resistor has 4 bands | Tolerance band is Gold (±5%) | Read as 2 digits + 1 multiplier. (e.g., Red-Red-Brown-Gold = 22 × 10 = 220Ω). |
| Resistor has 5 bands | Tolerance band is Brown (±1%) | Read as 3 digits + 1 multiplier. (e.g., Brown-Black-Black-Red-Brown = 100 × 100 = 10kΩ). |
| Resistor is SMD with 3 digits | Markings are purely numeric (e.g., 472) | Read as 2 digits + multiplier. (47 × 10² = 4.7kΩ). |
| Resistor is SMD with 2 digits + 1 letter | EIA-96 code (e.g., 01C) | Look up "01" in EIA-96 table (100), "C" = ×100. Result: 10kΩ. |
| Bands are burnt, faded, or missing | Visual ID is impossible or unreliable | Default Action: Desolder one leg and measure with a DMM on the ohms setting. |
Safe Interpretation When Markings are Faded or Missing
When a resistor has been subjected to thermal stress, the paint and color bands will blister, fade, or turn uniformly brown. Do not attempt to guess the value based on the physical size of the component; a 1/4W and 1/2W resistor can share the exact same resistance value but differ in power dissipation capability.
If you measure a faded resistor while it is still soldered into the PCB, your multimeter will read the equivalent resistance of the entire parallel circuit network, which will almost always be lower than the resistor's actual value. For an accurate reading, you must desolder at least one leg of the resistor to isolate it from the board's parallel paths.
Drift Characteristics by Material:
If you are repairing vintage gear (like 1970s audio amplifiers), be aware of material-specific aging. Old carbon composition resistors tend to increase in value over decades due to moisture absorption and internal cracking. Conversely, modern metal film resistors tend to remain stable or drift slightly downward under heavy thermal loads. If your multimeter reads 56kΩ on a faded resistor that looks like it should be 47kΩ, it is likely an old carbon comp that has drifted out of spec and must be replaced, not re-used.
When visual identification fails, your final, concrete step is always isolation and measurement. Desolder one leg, apply the DMM probes, and replace the component with a modern 1% metal film equivalent of the measured or schematic-specified value.
