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In aerospace engineering, payload fraction is a common term used to characterize the efficiency of a particular design. Payload fraction is calculated by dividing the weight of the payload by the weight of the otherwise empty aircraft when fully fueled. Fuel represents a considerable amount of the overall takeoff weight, and for shorter trips it is quite common to load less fuel in order to carry a lighter load. For this reason the useful load fraction calculates a similar number, but based on the combined weight of the payload and fuel together.
For spacecraft the payload fraction is often less than 1%, while the useful load fraction is perhaps 90%. In this case the useful load fraction is not a useful term, because spacecraft typically can't reach orbit without a full fuel load. For this reason the related term mass fraction, is used instead. However, if the latter is large, the payload can only be small.
|Vehicle||Takeoff Mass||Final Mass||Mass ratio||Mass fraction|
|Ariane 5 (vehicle + payload)||746,000 kg  (~1,645,000 lb)||2,700 kg + 16,000 kg (~6,000 lb + ~35,300 lb)||39.9||0.975|
|Titan 23G first stage||117,020 kg (258,000 lb)||4,760 kg (10,500 lb)||24.6||0.959|
|Saturn V||3,038,500 kg (~6,700,000 lb)||13,300 kg + 118,000 kg (~29,320 lb + ~260,150 lb)||23.1||0.957|
|Space Shuttle (vehicle + payload)||2,040,000 kg (~4,500,000 lb)||104,000 kg + 28,800 kg (~230,000 lb + ~63,500 lb)||15.4||0.935|
|Saturn 1B (stage only)||448,648 kg (989,100 lb)||41,594 kg (91,700 lb)||10.7||0.907|
|Virgin Atlantic GlobalFlyer||10,024.39 kg (22,100 lb)||1,678.3 kg (3,700 lb)||6.0||0.83|
|V2||13,000 kg (~28,660 lb) (12.8 ton)||3.85||0.74 |
|X-15||15,420 kg (34,000 lb)||6,620 kg (14,600 lb)||2.3||0.57|
|Concorde||~181,000 kg (400,000 lb )||2||0.5|
|Boeing 747||~363,000 kg (800,000 lb)||2||0.5|
Note: the above table may incorrectly include the mass of the empty upper stage or stages.