Looking at the characteristics of the different airplanes of the family 747-400Improved Aerodynamic Performance
The 747 400’s most noticeable aerodynamic improvement over previous 747s is the 6-foot (1.8 m) longer wing with a 6-foot-high winglet angled upward and slightly outward.
The winglet provides the effect of having an even greater wingspan without outgrowing the standard airport slot.
http://www.boeing.com/commercial/747fam ... index.html
the wing span, including the winglets, is 64.44 m (area 525 m2).
The only model without the 1.8 m wing tip extension + winglet is the 747-400 Domestic and the wing span is 59.6 m, exactly the same as the 747-100, 200 & 300.
The fact that in the models without winglets the wing area is smaller makes a bit questionable that a 20% area reduction was possible only thanks to the winglets.