Or $31,560 a year, given 2000 hours of work (50 weeks x 40 hours a week). Figures taken from this CNN.com story on the least affordable rental markets.
Given that this is the minimum amount required, and that you are not supposed to exceed 33% of your income for housing, this means the average rent for a two bedroom house in the US is $10,519 a year, or $877 a month.
In California, you need to make $22.09 an hour, or $44,180 a year. Thus, the average rent for a 2 bedroom in California is $14,726 a year, or $1,227 a month. In San Francisco, you need to make $29.54 an hour, or $59,080 a year to rent a house for $1,641 a month.
How does this compare to the price of houses?
In 2004, the median US house price was $221,000. In the last year, the median increase has been 12.02% for a 2005 price of just about $250,000. 30 year fixed rate mortgages are currently at 6.28%. Plugging these numbers into Excel, given a down payment of 10%, results in a payment of $1,390 a month. To be able to afford this payment, you would need to have an income of approximately $50,000 a year.
Only looking at the cash outflow, the difference between renting and buying in the US is about $513 a month.
It appears that right now is not a very good time to become a landlord.