Resistor Color Code Calculator⚡
Use this resistor color code calculator to quickly decode 4-band, 5-band, and 6-band resistor values. Select the resistor band colors to instantly calculate resistance, tolerance, and expected resistance range in ohms, kilo-ohms, or mega-ohms.
Decode 4, 5, and 6-band resistors, or reverse-calculate colors from a value.
Free Resistor Color Code Calculator
Determining the exact value of an axial-lead resistor can be confusing without a reference chart. Our free interactive calculator instantly translates standard 4-band, 5-band, and precision 6-band color codes into exact resistance values (Ω, kΩ, MΩ), complete with standard tolerance ranges and temperature coefficients.
How to Read Resistor Color Codes
Resistor color bands are always read from left to right. The bands grouped closely together represent the primary digits and the multiplier, while the single band offset to the right represents the manufacturing tolerance.
- The Digits: The first two bands (or three bands on precision resistors) represent the significant base numbers.
- The Multiplier: The next band determines how many zeros to add to the end of the base numbers (e.g., Orange = x1,000).
- The Tolerance: The offset band shows how much the actual resistance may vary from the stated value (e.g., Gold = ±5%).
How to Use the Calculator
We built this tool to work in two different directions for maximum utility:
- Color to Resistance: Select the number of bands your physical resistor has. Use the dropdowns (or simply click the bands on the graphic above) to match the colors you see on the component. The tool will automatically calculate the SI unit value, the expected minimum/maximum range, and identify the EIA standard series.
- Resistance to Color (Reverse): Need a specific resistor for a breadboard project but don't know what colors to look for? Click the "Resistance to Color" tab, type in your target value (like 4.7 kΩ), and the tool will instantly show you the exact color sequence you need to dig out of your parts bin.
4-Band vs 5-Band vs 6-Band Resistors
Not all resistors are created equal. The number of bands indicates the component's precision level:
- 4-Band Resistors: The most common general-purpose type. Uses 2 significant digits, 1 multiplier, and 1 tolerance band. Usually features Gold (±5%) or Silver (±10%) tolerances.
- 5-Band Resistors: Precision resistors. Uses 3 significant digits, 1 multiplier, and 1 tolerance band. This allows for much finer resistance values and usually features a Brown (±1%) or Red (±2%) tolerance.
- 6-Band Resistors: High-precision and military-spec resistors. Identical to a 5-band, but features a 6th band at the very end that indicates the Temperature Coefficient (how much the resistance shifts as the component heats up).
Tolerance and Temperature Coefficient
No manufacturing process is perfect. Tolerance dictates the maximum allowable error. For example, a 100Ω resistor with a Gold ±5% tolerance will safely measure anywhere between 95Ω and 105Ω. Temperature Coefficient (measured in ppm/°C) is critical for sensitive electronics; a 100 ppm/°C rating means the resistance will shift by 100 parts per million for every single degree Celsius the resistor heats up.
Resistor Color Code Chart
If you prefer to calculate manually, use this standard EIA color reference chart:
| Color | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | ×1 | — |
| Brown | 1 | ×10 | ±1% |
| Red | 2 | ×100 | ±2% |
| Orange | 3 | ×1k | — |
| Yellow | 4 | ×10k | — |
| Green | 5 | ×100k | ±0.5% |
| Blue | 6 | ×1M | ±0.25% |
| Violet | 7 | ×10M | ±0.1% |
| Gray | 8 | ×100M | ±0.05% |
| White | 9 | ×1B | — |
| Gold | — | ×0.1 | ±5% |
| Silver | — | ×0.01 | ±10% |
Common Resistor Values
Resistors are manufactured in standardized intervals known as E-series. The E12 series (10% tolerance) and E24 series (5% tolerance) are the most common in hobbyist electronics. Some of the most frequently used values in standard circuits include:
- 220 Ω (Red-Red-Brown): Standard LED Current Limiter
- 470 Ω (Yellow-Violet-Brown): General Purpose Pull-down
- 1 kΩ (Brown-Black-Red): Transistor Base Resistor
- 4.7 kΩ (Yellow-Violet-Red): I2C Data Line Pull-up
- 10 kΩ (Brown-Black-Orange): Standard Logic Pull-up/down
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Frequently Asked Questions
What is a resistor color code?
A resistor color code is an electronic industry standard (EIA) used to indicate the resistance value, tolerance, and sometimes the temperature coefficient of an axial-lead resistor. Color bands are painted onto the component's body because traditional through-hole resistors are often too small to print legible text or numbers on.
How do you read resistor color bands?
Always read resistor color bands from left to right. To find the correct orientation, look for a band that is spaced slightly further apart from the others—this is the tolerance band and it goes on the right. The bands clustered on the left represent your significant digits, followed by your multiplier band.
What does the gold band mean on a resistor?
The meaning of a gold band depends on its position. When it is the very last band on the right, it indicates a manufacturing tolerance of ±5%. If the gold band is acting as the multiplier (the band just before the tolerance), it means you multiply the preceding digits by 0.1.
How do you calculate resistor tolerance?
Tolerance represents the acceptable margin of error from the stated value. To calculate it, multiply the total calculated resistance by the tolerance percentage. For example, a 1,000 Ω resistor with a Gold band (±5%) can vary by 50 Ω, meaning its actual physical resistance will measure anywhere between 950 Ω and 1,050 Ω.
How do you read a 4-band resistor?
To read a 4-band resistor, hold the tolerance band (usually gold or silver, sitting slightly apart from the others) on the right. The first two bands represent the significant digits, the third band is the multiplier (how many zeros to add), and the fourth band is the tolerance percentage.
What is the difference between a 4-band and 5-band resistor?
A 5-band resistor is used for higher precision components. While a 4-band resistor only uses two significant digits before the multiplier, a 5-band resistor uses three significant digits before the multiplier, allowing for much more specific resistance values.
What does the 6th band on a resistor mean?
On a 6-band resistor, the first five bands operate exactly like a standard 5-band high-precision resistor. The 6th band indicates the Temperature Coefficient, which tells you how much the resistance will change as the component's temperature fluctuates (measured in ppm/K or ppm/°C).