Resistor Color Code Calculator
Calculate resistance value from color code, or reverse lookup color code from resistance value
How to Use
- Select "Color → Resistance" or "Resistance → Color" mode
- Select 4-band or 5-band
- In color mode, select the color of each band from the dropdown
- In resistance mode, enter the resistance value (you can use suffixes like k, M)
- The calculation result and visual resistor display are shown
Use Cases
- When reading resistance values from color codes of resistors at hand in electronics projects
- When looking up color codes for required resistance values in circuit design
- When checking the tolerance range of resistors and considering the operating range of the circuit
- When practicing how to read color codes in electronics learning
Frequently Asked Questions
What is the difference between 4-band and 5-band? ▼
4-band resistors consist of 4 bands: 2 significant digits + multiplier + tolerance. 5-band resistors consist of 5 bands: 3 significant digits + multiplier + tolerance, allowing more precise resistance values. 5-band resistors are often used in precision resistors.
What is tolerance (error)? ▼
It is a value indicating manufacturing variations in resistance. For example, a gold tolerance band means ±5%, and for a 100Ω resistor, the actual value will be in the range 95Ω to 105Ω.
What is the relationship with E series (E12, E24, etc.)? ▼
The resistance values that can be expressed with color codes are standard values based on the E series (JIS standard). This tool displays the color code closest to the entered resistance value.
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