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FreeUpdated Jan 2026CPA / EA Pro

IRS Penalty & Interest
Calculator 2025

Compute failure-to-file (FTF), failure-to-pay (FTP), and underpayment penalties with daily compounded interest. Includes maximum penalty caps, abatement eligibility estimate, and payment strategy recommendations.

Select Penalty Type & Enter Details
All calculations based on IRC §§ 6651, 6654, and current IRS interest rates
Penalty Type
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Failure to File
IRC § 6651(a)(1) — Late return penalty
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Failure to Pay
IRC § 6651(a)(2) — Late payment penalty
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Underpayment
IRC § 6654 — Estimated tax penalty
Tax Return Details
Tax Due on Return Unpaid balance as of original due date
$
Original Due Date
Date Filed (or today)
Extension Filed? Form 4868 filed by original due date
Prior Tax Compliance For First-Time Abatement eligibility
Total Owed
Tax + Penalty + Interest
Penalty Amount
Interest Accrued
Original Tax Due
Penalty
IRS Interest (~7% Q1 / 6% Q2 2026)
Total Amount Owed
Days Late
Months Late (for penalty)
📅 Penalty Accrual Timeline
🛡️ Penalty Abatement Analysis
First-Time Abatement (FTA) Eligible?
FTA Would Eliminate
After Abatement Owed
Form to FileForm 843 or Phone (1-800-829-1040)
Reasonable Cause?See AI Assistant for evaluation →
IRS Penalty Rules Explained
Failure-to-File (FTF) Penalty — IRC § 6651(a)(1)
5% of unpaid tax per month (or fraction thereof), up to a maximum of 25% (5 months). If both FTF and FTP apply in the same month, the FTF is reduced by the FTP rate, so the combined rate is still 5%/month. If the return is over 60 days late, the minimum penalty is the lesser of $525 (2025, filed 2026) or 100% of tax due.
Failure-to-Pay (FTP) Penalty — IRC § 6651(a)(2)
0.5% of unpaid tax per month, up to 25%. Reduced to 0.25%/month during an active installment agreement. Note: filing an extension gives more time to file but not more time to pay — the FTP penalty still accrues from the original due date.
IRS Interest Rate (2026)
IRS interest compounds daily at the federal short-term rate + 3%. The Q1 2026 rate is 7% per year; Q2 2026 dropped to 6% (subject to quarterly adjustment). Interest cannot be abated — only penalties can be reduced or eliminated.
First-Time Penalty Abatement (FTA)
Available if the taxpayer had no penalties in the prior 3 years and is otherwise compliant (filed returns and paid taxes). FTA eliminates the entire FTF or FTP penalty. Request by phone or via Form 843. This is the fastest and most commonly granted form of penalty relief.
📊 IRS Penalty Quick Reference
FTF Rate (per month)5.0%
FTF Maximum25%
FTP Rate (per month)0.5%
FTP w/ Installment Agmt0.25%
FTP Maximum25%
Min Penalty (60+ days late)$525 or 100%
IRS Interest Rate (2026)7% Q1 · 6% Q2+
Interest CompoundingDaily
FTA Lookback Period3 years
Form 843 (Abatement)Available
💡 Penalty Reduction Strategies
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Call the IRS first for FTA — it's often granted over the phone in minutes without filing Form 843.
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File even if you can't pay — the FTF penalty (5%/mo) is 10× the FTP penalty (0.5%/mo). Always file on time.
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Set up an installment agreement promptly — it cuts the FTP rate in half from 0.5% to 0.25%/month.
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Document reasonable cause — serious illness, natural disaster, or reliance on tax professional advice can support penalty waiver.