Free Tool
IRS Penalty & Interest Calculator
Estimate what the IRS is adding to your tax bill — the failure-to-file penalty, the failure-to-pay penalty, and daily interest at the current IRS rate. It runs privately in your browser; nothing is saved or sent.
How it works: the IRS charges 5% per month to file late (4.5% when the pay penalty also applies), 0.5% per month to pay late, and daily interest — currently 6% a year (the rate resets quarterly). Enter your numbers below for an estimate.
Estimated total you'd owe
$0
This is an estimate only, not a bill. The IRS uses your exact dates, resets the interest rate each quarter, charges interest on penalties too, and may apply a minimum late-filing penalty if your return is over 60 days late. Your real figures can differ — confirm before relying on this.
Penalties Adding Up? You May Be Able to Remove Them.
Many of these penalties qualify for first-time or reasonable-cause abatement. We'll review your case free, tell you honestly what's removable, and map the fastest way to stop the bleeding.
How IRS penalties and interest stack up
Three separate charges pile onto a late tax bill. The failure-to-file penalty is the big one — 5% of the unpaid tax every month, maxing out at 25% after five months. The failure-to-pay penalty is smaller but lasts longer — 0.5% a month up to 25%, and it keeps running for years. When both apply in the same month the IRS caps the combined rate at 5%, so the file penalty drops to 4.5%. On top of both, interest compounds daily at the federal short-term rate plus 3 points — 6% a year for the quarter beginning April 1, 2026, reset every quarter.
The good news: penalties are often removable. If you have a clean compliance history you may qualify for First-Time Abatement, and life events (illness, disaster, lost records) can support reasonable-cause relief. Interest generally can't be abated unless it relates to an IRS error — which is why stopping the penalties and the underlying balance quickly matters. If you can't pay in full, an installment agreement at least halves the pay penalty, and an offer in compromise may settle the whole thing.
Common questions
How much is the IRS failure-to-file penalty?
The failure-to-file penalty is 5% of the unpaid tax for each month or part of a month your return is late, up to a maximum of 25%. When the failure-to-pay penalty also applies in the same month, the failure-to-file penalty is reduced to 4.5%, so the combined penalty is 5% per month.
How much is the IRS failure-to-pay penalty?
The failure-to-pay penalty is 0.5% of the unpaid tax for each month or part of a month the tax is unpaid, up to a maximum of 25%. It drops to 0.25% per month while you are on an approved installment agreement.
What interest rate does the IRS charge?
For individuals, the IRS interest rate on unpaid tax is the federal short-term rate plus 3 percentage points, compounded daily. For the quarter beginning April 1, 2026 that rate is 6% per year. The rate is reset every quarter.
Clarity Tax Relief is not affiliated with the IRS or any government agency. This calculator is general information, not individualized tax or legal advice; exact penalties, interest, and eligibility depend on individual facts, and no outcome is guaranteed.
More tools: Offer in Compromise Calculator · CSED Calculator · IRS Help Center. Reviewed by Melissa Ly, Chief Tax Officer.