IRS Tax Debt Calculator
Enter what you owe and how long it has been due. The calculator estimates the penalties and daily-compounded interest the IRS has added, what the balance looks like a year from now, and a realistic monthly payment on a streamlined plan.
Interest is computed at 7% per year, the IRS underpayment rate for individuals for the quarter beginning July 1, 2026 (IRS quarterly interest rates). The rate resets every quarter.
Estimated total payoff today
$28,372
$25,000 in tax, plus an estimated $1,500 in penalties and $1,872 in interest after 12 months. Estimate only; your IRS transcript has the exact figure.
Estimated penalties
$1,500
Failure-to-pay penalty, capped at 25% of the tax. Filing on time avoided the larger 5%/month penalty.
Estimated interest
$1,872
Compounded daily at 7% per year (the rate for the quarter beginning July 1, 2026; it resets quarterly) on tax plus penalties.
In 12 more months
$31,989
$3,617 more if nothing changes. Interest never stops, and penalties keep running until they cap.
On a 72-month payment plan
about $394/month
Today's balance spread over 72 months, the standard streamlined term. Interest and a reduced failure-to-pay penalty continue to accrue during a plan, so actual payments run somewhat higher, or the plan pays off early if you overpay.
Email me my numbers, plus have a specialist sanity-check them
Educational estimate only, not tax advice. Actual IRS accruals depend on your exact assessment dates, payments and credits, notices issued (the failure-to-pay penalty rises to 1% per month after a final levy notice), and quarterly interest rate changes. This tool applies the current 7% rate across the whole period and assumes no payments. Your IRS account transcript is the authoritative number.
How the math works
- Failure-to-pay penalty: 0.5% of the unpaid tax for each month or part of a month, capped at 25%. It drops to 0.25% per month while an approved installment agreement is in effect (if you filed on time) and rises to 1% per month after a final notice of intent to levy. Source: IRS, Failure to Pay Penalty.
- Failure-to-file penalty: 5% of the unpaid tax per month for up to five months, capped at 25%. In months where both penalties apply, the failure-to-file penalty is reduced by that month's failure-to-pay penalty, which the calculator implements exactly. Once a return is over 60 days late, a minimum penalty applies: $525 for returns due after December 31, 2025, or 100% of the unpaid tax if smaller. Source: IRS, Failure to File Penalty.
- Interest: the federal short-term rate plus 3 percentage points, compounded daily, on tax plus penalties. For the quarter beginning July 1, 2026 that is 7% for individuals. The calculator applies today's rate across the whole period; the real rate changes quarterly. Source: IRS quarterly interest rates.
- Monthly payment: the estimated total divided by 72 months, the standard streamlined installment agreement term for balances of $50,000 or less in combined tax, penalties, and interest. Above that, plans run against the 10-year collection statute and usually require financial disclosure. Sources: IRS, Payment Plans and IRM 5.14.1.
For the full plain-English breakdown, read our guide to IRS penalties and interest and the IRS payment plan guide. If penalties make up a big share of your balance, penalty abatement may remove some of them, and the 10-year collection statute sets the outer clock on all of it.
Calculator questions
How much in penalties and interest does the IRS add to tax debt?
The failure-to-pay penalty adds 0.5% of the unpaid tax per month, up to 25%. If the return was never filed, the failure-to-file penalty adds 5% per month for the first five months, also capped at 25%. On top of both, interest compounds daily at the federal short-term rate plus 3 points, which is 7% for the quarter beginning July 1, 2026.
Does IRS interest apply to penalties too?
Yes. IRS underpayment interest accrues on the unpaid tax and generally on assessed penalties as well, and it compounds daily. That is why a balance keeps growing even after the penalties themselves hit their 25% caps.
What happens to penalties if I never filed the return?
A missing return triggers the failure-to-file penalty of 5% per month, ten times the pace of the failure-to-pay penalty. In months where both apply, the failure-to-file penalty is reduced by the failure-to-pay amount, and once a return is more than 60 days late a minimum penalty applies: $525 for returns due after December 31, 2025, or 100% of the unpaid tax if that is less.
How much would my IRS payment plan be per month?
A common starting point is your total balance divided by 72, the standard streamlined installment agreement term for balances of $50,000 or less in combined tax, penalties, and interest. Interest and a reduced 0.25% monthly failure-to-pay penalty continue during the plan, so real payments run somewhat higher than the simple division.
Do penalties and interest ever stop growing?
The failure-to-file and failure-to-pay penalties each stop at 25% of the unpaid tax, but interest never caps: it compounds daily until the balance is paid or the 10-year collection statute expires. Penalty abatement can remove penalties, and the interest charged on removed penalties goes with them.
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