The wire size for 100 amps depends on several factors, including the distance between the service panel and the electrical load, the surrounding temperature, and the voltage drop. Here are the recommended wire sizes for 100-amp service from the search results:

• 4 AWG or 2 AWG for copper wiring
• 2 AWG, 1 AWG, or 1/0 AWG for aluminum or copper-clad wiring
• #2 AWG wire for most 100-amp service panels
• 3 AWG THWN wire for a 100-amp subpanel
• 3 gauge (AWG) copper wire for a 100-amp subpanel
• #1 AWG wire for 100-amp service 100 feet away

Its important to note that these are general guidelines, and there may be specific local or regional codes that require you to use different wire sizes or configurations. Its always a good idea to consult with a local electrician who can install the wiring correctly and safely.