Apple's effective worldwide tax rate is ~25%, which is actually slightly higher than other US multinationals. That is also not counting taxes on income/capital gains paid by California employees, which are obviously pretty sizable.
"Apple’s effective U.S. federal income tax rate was just 7.3% in 2011. Apple claimed its tax rate in 2011 was 24.2%, one-third less than the official tax rate of 35%. But the Senate subcommittee found its rate was no more than 20.1%, allowing "Apple to claim credit for $3 billion of deferred taxes on overseas income that are not owed until the profits are brought back to the United States. Since Apple has said that is not likely to happen, its effective tax rate in 2011 was just 7.3% – $2.5 billion in taxes actually paid against $34.2 billion of income before taxes. [Exhibit 1a, pp. 38-39]"[0]
