Zurich - World champions Spain stayed atop the FIFA rankings on Wednesday, and the United States dropped five places in the top 20 despite not playing a match.
Spain lead from World Cup runners-up the Netherlands, with Brazil third and Germany fourth. The top 10 were unchanged after only two internationals involving lesser-ranked teams were played worldwide in the past month.
However, the US fell to No 18 because its four wins at the CONCACAF Gold Cup in July 2009 dropped in value.
FIFA has amended the complex formula - which ranks teams on results over four years - to give more value to matches played in three confederations.
South America now has equal weight with Europe, CONCACAF's status increased, and Africa is raised above Asia and Oceania.
FIFA said it made changes based on results at the last three World Cups, and will take effect for the next cycle leading to the 2014 finals in Brazil.
Egypt is the top African team ranked at No 9, even though the Africa Cup of Nations champion did not qualify for the 2010 World Cup. Ghana, which reached the quarter-finals in South Africa, is No 23.
The US leads the CONCACAF teams, while Mexico dropped one place to No 25.
Australia at No 20 heads the Asian confederation from 32nd-ranked Japan.
Oceania is headed by No 54 New Zealand, which was the only unbeaten team at the World Cup.
The September rankings will take account of more than 50 friendlies scheduled on Wednesday, and qualifiers for continental championships in Europe and Africa.
FIFA rankings released for August (July position in parentheses):
1. Spain (1)
2. Netherlands (2)
3. Brazil (3)
4. Germany (4)
5. Argentina (5)
6. Uruguay (6)
7. England (7)
8. Portugal (8)
9. Egypt (9)
10. Chile (10)
11. Italy (11)
12. Greece (12)
13. Serbia (13)
14. Croatia (15)
15. Paraguay (16)
16. Russia (17)
17. Switzerland (18)
18. USA (13)
19. Slovenia (19)
20. Australia (20)
Also:
66. South Africa (66)