I am filing as single, why is my standard deduction only $4,415? It should be $12,200.

[xmasbaby0]

Are you claimed as someone else's dependent?  If so that is why your standard deducition is lower.

[VolvoGirl]

Are you a dependent on someone else's return like your parents?  

If you are claimed as a dependent on someone else's return......

The Standard Deduction for an individual for whom an exemption can be claimed on another person's tax return is limited to the greater of:

…..$1,100 or

…..Your earned income for the year + $350 (but not more than 12,400)

So you would get a minimum of $1,100

See page 23 of Publication 501 and the worksheet on page 25

http://www.irs.gov/pub/irs-pdf/p501.pdf