🎨 Resistor Color Code Calculator
Select band colors to instantly calculate resistance, tolerance & temperature coefficient
📖 How to Use the Resistor Color Code Calculator
This resistor calculator helps you decode the color bands on through-hole resistors. Simply choose the band type (4-band, 5-band, or 6-band), then click the color swatches to match your physical resistor. The tool instantly displays the resistance value, tolerance, and temperature coefficient (for 6-band resistors).
🔍 Step-by-Step Guide
- Identify the number of bands on your resistor (4, 5, or 6).
- Click the corresponding band-type button at the top of the calculator.
- Starting from the band closest to one end, click each color swatch to match your resistor's bands.
- Read the calculated resistance in ohms (Ω), tolerance percentage, and temp coefficient.
- Use the Copy Result button to save the value for your project.
🎯 Understanding Resistor Color Codes
Resistor color codes are a standardized system for marking the value of axial-lead resistors. Each color represents a digit, multiplier, tolerance, or temperature coefficient. The system follows IEC 60062 international standards.
4-Band Resistor Color Code
The most common type. Bands 1 & 2 are significant digits, Band 3 is the multiplier, and Band 4 indicates tolerance. Example: Brown-Black-Red-Gold = 1-0-×100-±5% = 1,000 Ω (1 kΩ) ±5%.
5-Band Resistor Color Code
Used for precision resistors. Bands 1, 2 & 3 are significant digits, Band 4 is the multiplier, and Band 5 is tolerance. This allows for more precise values like 10.2 kΩ or 499 Ω.
6-Band Resistor Color Code
Same as 5-band, with an additional 6th band indicating the temperature coefficient in ppm/K. This tells you how much the resistance changes with temperature — critical for precision circuits.
📊 Resistor Color Code Chart
| Color | Digit | Multiplier | Tolerance | Temp Coeff (ppm/K) |
|---|---|---|---|---|
| Black | 0 | ×1 | — | 250 |
| Brown | 1 | ×10 | ±1% | 100 |
| Red | 2 | ×100 | ±2% | 50 |
| Orange | 3 | ×1K | — | 15 |
| Yellow | 4 | ×10K | — | 25 |
| Green | 5 | ×100K | ±0.5% | 20 |
| Blue | 6 | ×1M | ±0.25% | 10 |
| Violet | 7 | ×10M | ±0.1% | 5 |
| Grey | 8 | ×100M | ±0.05% | 1 |
| White | 9 | ×1G | — | — |
| Gold | — | ×0.1 | ±5% | — |
| Silver | — | ×0.01 | ±10% | — |
❓ Frequently Asked Questions
How do I know which end to start reading from?
Look for the band closest to one end of the resistor — that's Band 1. Also, the tolerance band (gold or silver) is usually on the right side. If both ends seem equally spaced, look for a wider gap between the last two bands on the tolerance end.
What is the difference between 4-band and 5-band resistors?
5-band resistors have an extra significant digit, allowing for greater precision. A 4-band resistor might be marked as 1.0 kΩ, while a 5-band equivalent could be 1.00 kΩ, offering more granular values for precision circuits.
Why does my resistor have only 3 bands?
Very old or specialized resistors may use 3 bands (no tolerance band), implying ±20% tolerance by default. However, 4-band is the modern standard for general-purpose resistors.
Can I measure resistance with a multimeter instead?
Absolutely! A multimeter gives you the actual measured value, which is more accurate than reading color codes (since resistors have tolerance ranges). But the color code calculator is invaluable when you don't have a multimeter handy or when the resistor is still in-circuit.
What does temperature coefficient mean?
The temperature coefficient (expressed in ppm/K) tells you how much the resistance changes per degree Celsius of temperature change. For example, a 100 ppm/K resistor will change by 0.01% for every 1°C change. This is crucial in precision analog circuits, sensor applications, and high-temperature environments.
