Resistor Calculator

Resistor color codes are read from left to right. The first two bands represent the significant digits, the third band is the multiplier, and the fourth band is the tolerance. For 5-band and 6-band resistors, the third band is also a significant digit, the fourth is the multiplier, the fifth is the tolerance, and the sixth (if present) is the temperature coefficient.

Tolerance indicates how much the actual resistance value can vary from the stated value. It’s expressed as a percentage. For example, a resistor with a 5% tolerance and a stated value of 100Ω could have an actual value between 95Ω and 105Ω.

The temperature coefficient indicates how much the resistance value changes with temperature. It’s measured in parts per million per degree Celsius (ppm/°C). A lower value means the resistance is more stable with temperature changes.

4-band resistors have two significant digits, one multiplier, and one tolerance band. 5-band resistors have three significant digits, one multiplier, and one tolerance band. 6-band resistors add a temperature coefficient band to the 5-band configuration, providing more precision and temperature stability information.

Gold and silver bands are typically used for tolerance values. Gold represents ±5% tolerance and silver represents ±10% tolerance. These metals are used because they’re easily distinguishable from the other color bands.