Has anyone else had a problem with the tax calculation? .

[rosemarie]

I changed the interest income on a return by $8 and the increase in federal tax was $11, which doesn't sound right.  I manually calculated with the 2018 Tax Rate Schedules and there was a discrepancy. The increase was only $2, not $11.

Taxable income                                                        $53,199          $53,207     increase $8

Tax calculated per Tax Rate Schedule                       $7,643           $7,645      tax increase $2

Tax calculated per  Intuit ProConnect Tax Online      $7,638           $7,649      tax increase $11

[George4Tacks · Accepted solution]

IRS in their infinite wisdom uses the tax tables and NOT the tax rate schedule. 

going from ....199 to ...200 moves from the ...150 to ...199 tax to the ...200 to ...249 tax. So a change of even $1 can cause extra tax on $50.

See page 73 https://www.irs.gov/pub/irs-pdf/i1040gi.pdf 

Tax is what you pay the big bucks for. PTO is correct 

[IRonMaN]

That's kind of vague.  Without real numbers I don't think anybody here can confirm whether the numbers are right or wrong.