I owe taxes this year and would like to set up an installment plan. I would like to know how they calculate penalties and interest when using this option.

[fanfare]

read about the various installment arrangements on the IRS website www.irs.gov

[scopeland]

None of that really helps me with knowing what the penalties and interest would be

[fanfare]

there is no penalty if you are approved for an installment plan. You pay interest until your balance is paid off.