I just happen to have an example handy for someone in California.
Gross wages: $28,000/yr
$ 1,736.00 FICA: 6.2%
$ 406.00 Medicare: 1.45%
$ 224.00 FUTA: 0.8%
$ 238.00 State UI: 3.4% on first $7k
$ 7.00 Employment Training Tax: 0.1% on first $7k
$ 1,812.00 Simple HMO plan @ $151/mo [pretty cheap!]
$ 2,422.00 Workers Comp @ 8.65% [varies depending on what you do,
but I've never seen one less than 7% and 14% isn't uncommon]
That's a total of $6,845 or about 25% and that's without any kind of pension or more than just an HMO health plan -- no long-term disability, no life insurance, no vacation, no overhead, etc.
For reference, this clears about $900/biweekly for the employee.
/jordan