How much IRS penalty and interest will I owe in 2026 or 2027 planning?
Use this IRS penalty and interest calculator to estimate how late filing, late payment, and unpaid tax balances may grow over time. It helps compare the cost of waiting with making a partial or full payment sooner.
IRS penalty and interest calculator
Quick answer
IRS penalties and interest depend on the unpaid tax amount, whether the return was filed late, how long payment is late, and the applicable interest rate. Paying sooner usually reduces total cost.
Also answers
- failure to pay penalty calculator
- late tax payment interest calculator
- failure to file penalty calculator
- IRS balance due calculator
Good fit when
- Estimating cost of a late tax payment
- Comparing filing late versus paying late
- Planning payment timing on an IRS balance
Have ready
- Unpaid tax balance
- Original due date, filing date, and payment date
- Penalty type and payment amount
Result you get
Estimated penalty, interest, and total balance growth.
How this calculation works
- Applies common failure‑to‑file and failure‑to‑pay rates.
- Estimates interest based on time outstanding.
- Shows a combined penalty and interest estimate.
Common mistakes and caveats
- Rates and rules can change each quarter.
- Actual penalty calculations depend on IRS determinations.
- Installment agreements can affect penalty rates.
FAQ
Can IRS penalties be reduced or waived?
In some cases, reasonable cause or first‑time abatement may apply.
TaxGuide Pro provides free state and federal tax calculators for individuals, freelancers, and small businesses.