IRS Penalty & Interest Estimator

Calculate failure-to-file and failure-to-pay penalties plus compounded interest based on current IRS rates.

How Penalties Work

Failure to File

Usually 5% of the unpaid taxes for each month or part of a month that a tax return is late. The maximum is 25%.

Failure to Pay

0.5% of the unpaid taxes for each month or part of a month the tax remains unpaid. Combined with filing penalty, the 0.5% is deducted from the 5%.

Interest Rates

Determined quarterly by the IRS. This tool uses historical quarterly rates and estimates future accruals based on the most recent published rate.

Last Tool Update: April 26, 2026