Tax years 2019–2025

Federal Individual Penalty & Interest Calculator

Estimate ordinary late-filing and late-payment costs for a federal individual income-tax balance. No account login or taxpayer identifiers required.

Use this as an educational estimate—not an IRS payoff amount.

This version does not calculate estimated-tax penalties, state liabilities, business-return penalties, payment plans, levy-rate changes, relief provisions, or IRS-assessed interest on penalties.

Return and balance

For ordinary federal Forms 1040 and 1040-SR only.

Tax year

Tax unpaid on the payment due date

Tax still unpaid when the return was filed

Dates

Nationwide postponed deadlines for 2019 and 2020 are built in. Special disaster and combat-zone relief is not.

A valid extension to file was submitted by the original deadline. This changes the late-filing start date, but not the payment due date.

Actual return filing date

Calculate unpaid costs through

Built-in assumptions

The ordinary failure-to-pay rate is 0.5% for each month or partial month.
When both ordinary penalties apply, the late-filing portion is estimated at 4.5% per month for up to five months.
Tax interest uses published quarterly individual underpayment rates and daily compounding.
Interest on assessed penalties is excluded because the assessment date is not known.

Methodology sources: IRS failure-to-file rules, IRS failure-to-pay rules, IRS quarterly interest rates, and IRS interest guidance. Last reviewed July 13, 2026. Calculator version 1.0.