What Is the Temperature of a Light Bulb Filament?

The temperature of the filament of an incandescent light bulb is between approximately 2800 and 3700 Kelvin. This is somewhere between 4500 and 6200 degrees Fahrenheit.

The filament of most incandescent light bulbs today is made of tungsten. Tungsten has a melting point of 3422 degrees Celsius, or slightly under 3700 Kelvin. When electric current is passed through the filament, the temperature of the filament increases. In order to maintain the integrity of the filament, the current is sufficiently low that the filament does not completely evaporate. However, in order for the filament to radiate energy in the wavelengths of visible light, the current also needs to be sufficiently large.