Tax Bill Payment Plan Calculator
Estimate how long an IRS installment plan takes and what interest and penalties add, given your balance and a fixed monthly payment.
How it works
Each month: charge = balance × (rate ÷ 12), balance = balance + charge − payment · repeat until cleared
When you owe the IRS and set up an installment agreement, the balance keeps accruing interest plus a failure-to-pay penalty until it is gone, so the longer you take the more it costs. The combined rate is typically in the high single digits, meaningfully less than most credit cards, which is why an IRS plan usually beats charging the bill. Paying more each month shortens the term and cuts the interest and penalties sharply.
Worked example
A $6,000 balance at roughly 8% combined interest and penalty, paid at $300 a month, clears in about 21 months and adds around $450 in interest and penalties, for about $6,450 total.
Frequently asked questions
Does the IRS charge interest on payment plans?
Yes — interest and, in most cases, a failure-to-pay penalty continue to accrue on the unpaid balance until it is fully paid, even on an approved installment agreement. The penalty rate is reduced while an agreement is in place.
Is an IRS payment plan cheaper than a credit card?
Usually, because the combined IRS interest-and-penalty rate is typically well below credit-card APRs. This calculator lets you compare by changing the rate to your card’s APR.
How can I pay less overall?
Pay as much as you can as fast as you can — interest and penalties accrue on the remaining balance, so a higher monthly payment shortens the term and lowers the total. Paying the balance in full stops all further charges.
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Educational estimate, not financial advice. Actual IRS interest and penalty rates change quarterly — confirm current figures with the IRS.