Resistor Color Code Calculator (4-Band)

Reading a 4-band resistor is straightforward: the first two bands represent significant digits, the third band is the multiplier, and the fourth band indicates tolerance. For example, Brown-Red-Red-Gold equals 12 × 100Ω = 1.2kΩ with ±5% tolerance.

4-band resistors have two significant digits and are typically ±5% or ±10% tolerance, suitable for general applications. 5-band resistors have three significant digits offering higher precision with ±1% or ±2% tolerance for more critical circuits.

Use a digital multimeter to measure the actual resistance value, or ask someone to help identify the colors. Some mobile apps can also identify resistor colors using your phone's camera to help with color recognition.

The tolerance band indicates how much the actual resistance can vary from the nominal value. Gold means ±5%, silver means ±10%, and other colors indicate tighter tolerances like brown (±1%) or red (±2%).

No, this calculator is specifically for axial through-hole resistors with color bands. Surface mount resistors use numerical codes printed on them instead of color bands, requiring a different decoding method.

This calculator is designed for 4-band resistors only. If your resistor has 3, 5, or 6 bands, you'll need a different calculator or reference chart as the color code interpretation varies with the number of bands.

The first band represents the first significant digit, and starting with zero would be meaningless (like writing 047 instead of 47). Therefore, 4-band resistors typically start with brown (1) through white (9) for the first band.

The min/max values show the acceptable resistance range based on the tolerance band. For example, a 1kΩ resistor with ±5% tolerance will measure between 950Ω and 1050Ω when tested with a multimeter.