<prompt> Human: Im using turbo tax. After entering my W-2, I would receive a tiny refund from my 55,000 income. When adding 10,000 of self-employment income, I now apparently owe 4,000.Is this correct? It seems way off to me.Thanks!Assistant: Yes seems correct to me. On the 10k you would owe 15 fica taxes a 25 marginal federal tax rate which is 40 tax on 10k. Human: Thanks, where does the 25 come from?  <response>: You owe income tax and self employment tax on your profit. 