The exact resistor 500 ohm color code depends on the number of bands printed on the component body. For a standard 4-band resistor, the colors are Green, Black, Brown (followed by a Gold or Silver tolerance band). For a 5-band precision resistor, the colors are Green, Black, Black, Black (followed by a Brown or Red tolerance band).
However, before you dig through your component bin, note a critical bench reality: 500Ω is a non-standard value in the common E24 and E96 series. You are far more likely to find 510Ω or 499Ω in a modern kit. If you specifically need 500Ω, you will typically find it in wirewound power resistors, older carbon composition stock, or custom manufacturing runs. Below is the exact breakdown of how to identify, verify, and substitute this value.
The 500 Ohm Resistor Color Code Reference Table
The table below maps the physical bands to their mathematical values. Always read the bands starting from the end closest to the lead, moving toward the tolerance band (usually Gold or Silver) on the right.
| Band Position | 4-Band Code (±5% Tolerance) | 5-Band Code (±1% Tolerance) | Mathematical Function |
|---|---|---|---|
| Band 1 (1st Digit) | Green (5) | Green (5) | First significant digit |
| Band 2 (2nd Digit) | Black (0) | Black (0) | Second significant digit |
| Band 3 (3rd Digit / Multiplier) | Brown (×10) | Black (0) | Third digit (5-band) or Multiplier (4-band) |
| Band 4 (Multiplier / Tolerance) | Gold (±5%) | Black (×1) | Multiplier (5-band) or Tolerance (4-band) |
| Band 5 (Tolerance) | N/A | Brown (±1%) | Final tolerance rating |
| Calculation | 50 × 10 = 500Ω | 500 × 1 = 500Ω | Final Nominal Value |
Standard Variants: IEC 60062 vs. Wire Codes & Legacy Specs
A common point of confusion for beginners crossing over from home wiring to electronics is assuming component color codes change by region like electrical wire codes do. They do not.
Resistor Standards (Global): All modern resistor color codes are governed globally by IEC 60062. Whether you buy a resistor in Tokyo, Berlin, or Chicago, Green-Black-Brown will always mean 500 ohms. There are no regional variants for component bands.
Wire Color Codes (Regional): Do not confuse resistor bands with mains wiring insulation. Mains wiring is strictly regional. In the US, the NEC mandates Black (Hot), White (Neutral), and Bare/Green (Ground). In the EU and modern UK, IEC 60446 mandates Brown (Live), Blue (Neutral), and Green-Yellow (Earth). Old UK wiring (pre-1970s) used Red, Black, and Green. Applying wire color logic to component bands will result in immediate misidentification.
Rows People Get Wrong (and Faded Band Recovery)
When reading the resistor 500 ohm color code on the bench, two specific errors account for 90% of misidentifications.
1. The Multiplier Confusion (Brown vs. Black)
In a 4-band resistor, the third band is the multiplier. For 500Ω, this must be Brown (×10). However, under warm bench lighting or on cheap carbon film resistors, Brown can easily look like Red (×100) or Black (×1).
- If you read it as Black (×1), you will calculate 50Ω. Your circuit will draw 10x the expected current.
- If you read it as Red (×100), you will calculate 5,000Ω (5kΩ). Your biasing network will starve the transistor or op-amp.
2. Orientation Errors on 5-Band Resistors
On a 5-band 500Ω resistor (Green-Black-Black-Black-Brown), the first four bands are all dark colors. It is incredibly easy to read the resistor backward, starting from the Brown tolerance band. If read backward, the sequence Brown-Black-Black-Black-Green translates to a nonsensical or entirely different value depending on how your brain parses the tolerance. Rule of thumb: The tolerance band (Gold, Silver, or Brown) is always spaced slightly further apart from the other bands and is positioned on the far right.
Safe Interpretation for Faded or Burnt Bands
If a resistor has been subjected to overcurrent, the heat will bake the paint, turning Green and Blue into a uniform muddy brown. When visual identification fails, never guess.
- Desolder one leg of the resistor to isolate it from the parallel paths of the PCB.
- Set your multimeter to the resistance (Ω) mode.
- Measure across the leads. If it reads ~495Ω to 505Ω, you have confirmed the 500Ω value regardless of the faded paint.
For more on measurement techniques and isolation, reference the All About Circuits guide on resistor identification and testing.
Frequently Asked Questions
Is 500 ohm a standard E24 or E96 resistor value?
No. The standard E24 series (5% tolerance) jumps from 470Ω to 510Ω. The precision E96 series (1% tolerance) jumps from 487Ω to 499Ω, then to 511Ω. A true 500Ω resistor is considered a non-standard "round number" value. You will rarely find it in a standard 1/4W metal film kit. If a schematic specifically calls for 500Ω, it is usually a wirewound power resistor, a custom-manufactured batch, or the designer was using a rounded theoretical value and actually intended for you to use 499Ω or 510Ω.
How do I read a 500 ohm resistor if the brown multiplier band looks red?
If the third band on a 4-band resistor looks Red instead of Brown, you are likely looking at a 5,000Ω (5kΩ) resistor, not a 500Ω resistor. Red indicates a multiplier of ×100 (50 × 100 = 5,000). To verify, use a digital multimeter. If the meter reads ~5kΩ, the band is Red. If the meter reads ~500Ω, the paint is simply faded or discolored by heat, and it is indeed a 500Ω resistor with a Brown band.
Can I substitute a 510 ohm or 499 ohm resistor for a 500 ohm requirement?
In 95% of hobbyist and general electronics applications, yes. A 510Ω resistor is only 2% higher than 500Ω, and a 499Ω resistor is only 0.2% lower. For LED current limiting, pull-up/pull-down networks, and basic voltage dividers, this variance is completely negligible and will not affect circuit operation. However, if you are building a precision analog circuit—such as a DAC reference ladder, a medical sensor frontend, or a precision current shunt—you must use the exact specified value. In those cases, use a 499Ω 0.1% precision resistor or a 500Ω multi-turn trimpot to dial in the exact resistance.
