Line 44 is the tax on your income before the withholding is subtracted. It comes from the Tax Table or is a complicated calculation depending on the kind of income you have.
Here is the 2014 Tax Table
https://www.irs.gov/pub/irs-prior/i1040tt--2014.pdf How the Tax is calculated:
You add up all your income to get the Adjusted Gross Income on 1040 line 37
Then you get to subtract the Standard Deduction (12,400 for 2014) or your Itemized deductions whichever is more (line 40)
Then you get to subtract all your personal exemptions and dependents (3,950 each for 2014) on line 42
That is your Taxable Income on line 43
The Tax is calculated on your Taxable Income. But if you have any Long Term Capital Gains or Qualified Dividends the tax is calculated on a special worksheet.
But if you want to call in Contact Customer Service
https://ttlc.intuit.com/replies/3300041