Boeing 757 Variants
It has been manufactured in two basic variants.
Variants
The 757-200 is shorter and has a longer operating range than the 757-300. The -100 was to be a variant but was not built. Some airlines truncate the full designations of these aircraft, and refer to them as the 752 and 753.
757-100
This is the initial design with 150 seat capacity which is the direct replacement of the 727. It failed to generate interest and was not built.
757-200
The 757-200 is the definitive version and forms the majority of the 757. It has also been 
manufactured in freighter (757-200F) and passenger-freight combo (757-200M) versions. In the late 1990's some of the passenger 757-200 series were converted to dedicated freighters.
The passenger-carrying versions of the 757-200 was available in two different door configurations. One version used three standard doors per side with an additional, smaller door aft of the wing on each side for emergency evacuations. All eight door locations are equipped with inflatable evacuation slides. The alternate version is equipped with three standard doors per side (two towards the front and one at the aft of the cabin) with two "plug-type" overwing exits per side replacing the smaller door aft of the wing.
•757-200ER : Extended range version, never went past design phase. Some airlines have given this title to their higher gross weight versions, especially on intercontinental applications.
•757-200PF : Package freighter version.
•757-200SF : Special freighter version for DHL.
757-300
The 757-300 is a stretched version, trading range for passenger capacity and the plane first flew in August 1998. The 757-300 is configured to carry 252 passengers. Range is 3,500 n.mi. Only 55 were ordered. This model has 8 standard doors, with 4 over-the-wing exit doors, 2 on either side. This model also features the interior of the Next Generation 737, which blends aspects of the 757-200 interior with the Boeing 777-style interior.