How to use the resistor color code calculator
To use the resistor color code calculator click on the resistor color bands on the left. Then you can select the color for each band. The calculator will automatically show you the resistance value, tolerance, and temperature coefficient band. You can also use the up and down arrows to change the band colors sequentially. Use the selector to switch between 4-band, 5-band, and 6-band resistor formats.
What is the Resistor Color Code
Axial resistors (also called thru-hole resistors) use a color-band system (EIA) to indicate their nominal resistance, tolerance, and, in some cases, temperature coefficient. Each color corresponds to a specific number or multiplier. For example, black represents 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, gray 8, and white 9. The colors for multipliers and tolerances are also standardized. This coding system allows manufacturers to label very small components without printing text. Band meaning summary:
- First and second band: significant digits
- Third band: multiplier
- Fourth band: tolerance
- Fifth band (if present): extra significant digit (it is in 3rd position after first and second bands)
- Sixth band (if present): TCR (temperature coefficient)
Resistor color codes are standardized according to international electronics norms and are used in almost all through-hole axial resistors.
Once you have decoded the part value, the resistor network calculator helps when it joins other resistors, and the Ohm's law calculator helps you see what that value means electrically.
Resistor Color Code Chart
The resistor color code chart summarizes the digits, multipliers, and tolerances assigned to each color. It is the universal reference used to decode through-hole resistors.
You can download the resistor color chart as a PNG:
Download chart.
4-band resistor color code
A 4-band resistor uses two significant digits, one multiplier band, and one tolerance band. Example: brown-black-red-gold = 1 kΩ ±5%.
5-band resistor color code
A 5-band resistor uses three significant digits, one multiplier band, and one tolerance band. Example: yellow-violet-black-brown-brown = 4.7 kΩ ±1%.
6-band resistor color code
A 6-band resistor follows the same reading order as a 5-band part, with the extra band indicating temperature coefficient (TCR). This is common in precision resistors.
What is Resistor Tolerance?
Tolerance indicates how much the actual resistance can vary from its nominal value. For example, a 1 kΩ resistor with ±5% tolerance may range between 950 Ω and 1050 Ω. Low-tolerance resistors (1%, 0.1%) are used in precision circuits, sensors, filters, and applications where stable and predictable resistance is required.
What is TCR (Temperature Coefficient of Resistance)?
The Temperature Coefficient of Resistance (TCR) describes how much the value of a resistor changes with temperature. It is expressed in parts per million per degree Celsius (ppm/°C). A lower TCR means better thermal stability. For example, imagine a 10 kΩ resistor with a TCR of 100 ppm/°C. If the temperature rises from 25 °C to 50 °C (a 25 °C increase), the resistance change is:
100 ppm x 25 °C = 2500 ppm = 0.25%
This means the resistor will increase by 0.25% of its nominal value:
10 kΩ x 0.0025 = 25 Ω,
so at 50 °C the resistor would be approximately 10025 Ω. Resistors with low TCR values are essential in precision analog circuits, oscillators, feedback networks, and any application where temperature variations can affect performance.
Worked examples
Example 1: Brown – Black – Red – Gold corresponds to 1 kΩ ±5%.
Example 2: Yellow – Violet – Black – Brown – Brown corresponds to 4.7 kΩ ±1%.
If you add a sixth brown band to a precision resistor, the TCR becomes 100 ppm/°C.
Frequently Asked Questions
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How do you read a 4-band resistor?
First two bands are digits, third is the multiplier, fourth is tolerance.
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How do you read a 5-band resistor?
Three digits, one multiplier, and a tolerance band.
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How do you read a 6-band resistor?
Same as 5-band, with an extra band indicating TCR (temperature coefficient).
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Why do resistors use color codes?
Because axial resistors are too small to print values on, so standardized color bands are used instead.
