Turkish Airlines' excess baggage allowance policy depends on the route and fare type.

For most international flights, including flights between the United States and Turkey, the excess baggage fee varies depending on the weight and destination. The fee for each extra kilogram of baggage may range from $5 to $20, and the maximum weight allowed for a single piece of checked baggage is generally 32kg.

Passengers can check the specific excess baggage fee for their route and fare type on the Turkish Airlines website or by contacting the airline's customer service. It's recommended to check with the airline before traveling to avoid any surprises or additional fees at the airport.