When you pull a through-hole resistor from your parts bin, the painted bands tell you its exact resistance and tolerance at room temperature. The standard 4 band resistor color code is governed by the IEC 60062 international standard (historically aligned with EIA RS-279). Band 1 and Band 2 represent the significant digits, Band 3 is the decimal multiplier, and Band 4 indicates the manufacturing tolerance. While the colors give you the nominal ohmic value, they do not tell you the component's power limits, voltage ceiling, or high-frequency parasitics—specs that will destroy your circuit if ignored.
The Complete 4 Band Resistor Color Code Table (IEC 60062)
How to read this table: Read the bands from left to right, keeping the tolerance band (usually Gold or Silver) on the far right. Match the first two bands to the Digit column to get your base number. Match the third band to the Multiplier column to determine how many zeros to append (or decimal places to shift). Finally, check the Tolerance column to see your acceptable variance. Which column applies to your installation? If you are building a precision analog front-end or a voltage divider for an ADC reference, the Tolerance column dictates whether a standard 4-band (±5%) part is acceptable, or if you must upgrade to a 5-band (±1% or ±0.1%) metal film resistor to prevent measurement drift.
| Band Color | Digit (Bands 1 & 2) | Multiplier (Band 3) | Tolerance (Band 4) |
|---|---|---|---|
| Black | 0 | ×1 Ω (10⁰) | — |
| Brown | 1 | ×10 Ω (10¹) | ±1% (F) |
| Red | 2 | ×100 Ω (10²) | ±2% (G) |
| Orange | 3 | ×1 kΩ (10³) | — |
| Yellow | 4 | ×10 kΩ (10⁴) | — |
| Green | 5 | ×100 kΩ (10⁵) | ±0.5% (D) |
| Blue | 6 | ×1 MΩ (10⁶) | ±0.25% (C) |
| Violet | 7 | ×10 MΩ (10⁷) | ±0.1% (B) |
| Grey | 8 | — | ±0.05% (A) |
| White | 9 | — | — |
| Gold | — | ×0.1 Ω (10⁻¹) | ±5% (J) |
| Silver | — | ×0.01 Ω (10⁻²) | ±10% (K) |
Source: IEC 60062:2016 / All About Circuits Resistor Color Codes
Quick-Jump Lookup: The 15 Most Common 4-Band Values
Bookmark this section for the bench. These are the E24 series values you will reach for 95% of the time in general-purpose DIY electronics, LED current limiting, and microcontroller pull-up/pull-down networks.
| Target Value | Band 1 | Band 2 | Band 3 (Multiplier) | Band 4 (Typical) |
|---|---|---|---|---|
| 100 Ω | Brown | Black | Brown | Gold |
| 220 Ω | Red | Red | Brown | Gold |
| 330 Ω | Orange | Orange | Brown | Gold |
| 470 Ω | Yellow | Violet | Brown | Gold |
| 1 kΩ | Brown | Black | Red | Gold |
| 2.2 kΩ | Red | Red | Red | Gold |
| 3.3 kΩ | Orange | Orange | Red | Gold |
| 4.7 kΩ | Yellow | Violet | Red | Gold |
| 10 kΩ | Brown | Black | Orange | Gold |
| 22 kΩ | Red | Red | Orange | Gold |
| 47 kΩ | Yellow | Violet | Orange | Gold |
| 100 kΩ | Brown | Black | Yellow | Gold |
| 220 kΩ | Red | Red | Yellow | Gold |
| 470 kΩ | Yellow | Violet | Yellow | Gold |
| 1 MΩ | Brown | Black | Green | Gold |
Beyond the Colors: Power Derating and Hidden Specs
The color code chart only solves half the selection problem. It tells you the resistance, but it completely omits the physical limits of the component. Here is what the color bands cannot tell you, and how to look up the missing data.
You cannot determine a resistor's wattage from its bands. Wattage is dictated by the physical mass and surface area of the component. A standard 1/4W (0.25W) axial carbon or metal film resistor typically uses an 0207 body size (approx. 6.3mm long x 2.3mm diameter). A 1/2W resistor uses a larger 0309 body. Always verify the physical size against your BOM.
How Derating Rows Modify the Base Value
Every resistor datasheet includes a Power Derating Curve (often based on MIL-PRF-55342 or manufacturer specs like Vishay's CRCW series guidelines). A 1/4W resistor is only rated for 0.25W at an ambient temperature of 70°C or lower. If your installation is inside a sealed enclosure that reaches 100°C, you must consult the derating table. At 100°C, the derating curve typically drops the allowable power to roughly 60% of the base value (0.15W). By 155°C, the allowable power drops to 0W. If your circuit operates in a high-ambient environment, you must physically upsize to a 1/2W or 1W resistor just to maintain the same thermal headroom.
What the Table Cannot Tell You: Voltage and Parasitics
- Maximum Working Voltage: Ohm's law ($V = \sqrt{P \times R}$) suggests a 1/4W, 1 MΩ resistor can safely handle 500V ($\sqrt{0.25 \times 1,000,000}$). In reality, the physical gap between the lead wires and the dielectric strength of the epoxy coating limits standard 1/4W resistors to a 250V maximum working voltage. Exceeding this causes internal arcing, regardless of the wattage rating.
- Parasitic Inductance: Standard axial through-hole resistors are essentially wirewound or helical-cut films. They exhibit 1 nH to 2 nH of parasitic inductance. If you are building an RF snubber or a high-speed digital termination network operating above 10 MHz, a standard 4-band axial resistor will act like an inductor. You must switch to surface-mount (SMD) or specialized non-inductive axial resistors.
- Pulse Energy Handling: A 1/4W resistor can handle 0.25W continuously, but it can survive a 10W pulse for a few milliseconds. The color code gives no indication of this surge capability; you must check the manufacturer's pulse limit charts for snubber or inrush-limiting applications.
4 Band Resistor Chart FAQ
Which way do I read a 4 band resistor?
Always read from left to right, starting with the band closest to the lead wire. The easiest way to orient the component is to locate the tolerance band first. On a 4 band resistor, the 4th band is almost always Gold (±5%) or Silver (±10%), and it is typically spaced slightly further apart from the first three bands. Position the Gold or Silver band on the far right, then read the first three bands left-to-right.
Why does my 4 band resistor have a 5th band?
If you see five bands, you are either holding a high-precision resistor or a legacy military-spec part. Modern 5-band resistors use the first three bands for significant digits, the fourth for the multiplier, and the fifth for tolerance (yielding ±1% or better). However, some older military-spec 4-band resistors feature a 5th band indicating the reliability coefficient (failure rate per 1,000 hours). If the 5th band is distinctly separated and the part looks vintage, check a MIL-SPEC datasheet. For 99% of modern hobbyist and commercial boards, a 5th band means it's a high-precision 3-digit resistor.
How do I calculate the wattage of a 4 band resistor from its colors?
You cannot. The color bands strictly denote resistance and tolerance. Wattage is determined entirely by the physical dimensions, mass, and material of the resistor body. If you need to identify the wattage of an unmarked resistor in your bin, measure its length and diameter with calipers and compare it to standard IEC 60063 body size charts (e.g., 6.3mm x 2.3mm is typically 1/4W, 11.0mm x 4.0mm is typically 1W).
Can I replace a 5% 4-band resistor with a 1% 5-band resistor?
Yes, substituting a tighter tolerance part is almost always electrically safe and often improves circuit accuracy. The primary risk is physical, not electrical: 1% metal film resistors sometimes use slightly different body coatings or lead spacing than cheap 5% carbon film parts. Ensure the lead pitch (usually 10mm or 15mm on standard through-hole boards) matches your PCB footprint, and verify that the replacement part meets the same voltage and power derating requirements.
