Penalty Projection Calculator

See how much your tax debt will grow over time

1. Balance

2. Settings

3. Results

Enter Your Current Tax Debt

Current Tax Balance Owed *

The principal tax amount you owe (excluding penalties and interest if entering separately)

Optional: Existing Penalties & Interest

If you already have penalties or interest on your account (from an IRS notice), enter them here.

Interest Already Accumulated

FTP Penalty Already Accumulated

About This Calculator

This calculator projects how your IRS tax debt will grow over time due to interest (compounded daily per IRC § 6622) and penalties (FTP at 0.5%/month, FTF at 5%/month). Use it to understand the true cost of waiting and make informed payment decisions.

• Interest is compounded daily at the federal short-term rate + 3% (or +5% for large corporations)
• FTP penalty maxes out at 25% (50 months)
• FTF penalty maxes out at 25% (5 months) - file your return to stop this
• Consider requesting FTA (First-Time Abatement) to eliminate penalties