List of tram systems by gauge and electrification

The following is a list of tram/streetcar (including heritage trams/heritage streetcars), or light rail systems with their track length, track gauge, electrification system.

The majority of tram systems use 1,435 mm (4 ft 8+12 in) standard gauge. Standard gauge is used for most new systems (except in the former Soviet Union where Russian gauge is used), even in places where another gauge is used for heavy rail systems. Metre gauge is mainly present in some older systems in Central Europe.

The electrification system for older systems is generally 600 V DC while more recent systems use 750 V DC. Some old systems upgraded to 750 V in recent years (mostly in Germany) while some systems (e.g. Romania) downgraded the voltage to 600 V to use the second-hand vehicles coming from the upgraded German networks. Most systems draw power from overhead catenary wires, while some use APS and ACR systems or internal power sources such as battery or ultracapacitors. A few vintage systems are horse-drawn tram or cable car.