Resistor Color Code Calculator
Interactive electronics utility to instantly decode the resistance value, tolerance, and temperature coefficient of 4-band, 5-band, and 6-band axial resistors.
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100% Local Processing. All color decoding and calculations happen securely within your browser.
How to Use the Resistor Color Code Calculator
- Select the number of color bands on your resistor (4, 5, or 6).
- Click on the colored bands in the visualizer to set the correct colors from left to right.
- The tool will automatically decode the digit bands and apply the multiplier.
- Read the final Resistance Value, Tolerance Percentage, and Temperature Coefficient (for 6-band).
Frequently Asked Questions
How do you read a 4-band resistor color code?
In a 4-band resistor, the first two bands represent significant digits, the third band is the multiplier, and the fourth band is the tolerance.
What is the difference between a 4-band and 5-band resistor?
A 5-band resistor has an extra significant digit band. The first three bands are digits, the fourth is the multiplier, and the fifth is the tolerance, allowing for higher precision values.
What does the 6th band on a resistor mean?
The 6th band on a resistor indicates the Temperature Coefficient (TCR), which specifies how much the resistance changes as the temperature changes, measured in ppm/K (parts per million per Kelvin).
Which side of the resistor do I read from?
Read the resistor starting from the side where the color bands are grouped closest together. The tolerance band (usually Gold or Silver) is typically spaced slightly further apart on the right side.
What is the Gold band on a resistor?
A Gold band typically represents the Tolerance of the resistor. When it is the last band, Gold means a +/- 5% tolerance. If Gold is used as a multiplier (3rd or 4th band), it multiplies the value by 0.1.
Can I use this for SMD resistors?
No, this tool is designed for through-hole resistors with color bands. Surface-mount (SMD) resistors use a numerical code printed on top (like 103 or 472), which requires an SMD code calculator.
What color is a 10k ohm resistor?
For a standard 4-band 10k resistor, the colors are Brown, Black, Orange, and a tolerance band (e.g., Gold). (1, 0, x1000 = 10,000 ohms).
Is a resistor directional?
No, resistors are passive components and do not have polarity. You can install them in a circuit in either direction, though it's standard practice to orient them so the color bands can be read left-to-right.
Limitations
This tool decodes standard EIA color codes for through-hole resistors. It does not support military specification (MIL-SPEC) cylindrical resistors which may have a wider first band indicating wirewound construction, nor does it decode alphanumeric surface mount (SMD) codes.
Data Privacy & Security
Our Resistor Color Code Calculator runs entirely in your web browser. No measurements or engineering data are sent to any external servers, ensuring complete privacy.