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IRS Penalty Calculator

Estimate IRS penalties for late filing, late payment, or underpayment of estimated taxes based on the amount owed and how many days past the deadline you are. Helpful for taxpayers deciding whether to file for an extension or pay immediately.

Tax Amount Owed ($)

Days Late (days)

Penalty Type

Reasonable Cause Expected

Fill in the required fields to see your result.

Taxes

Tax Bracket Calculator

Identifies your top marginal federal income tax bracket — the rate that applies to your next dollar of taxable income — based on 2023 IRS bracket thresholds and your filing status. Useful for marginal-rate decisions like Roth conversions, capital-gain harvesting, charitable bunching, and side-income trade-offs.

Taxable Income ($)

Filing Status

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Key differences

	IRS Penalty Calculator	Tax Bracket Calculator
Category	Taxes	Taxes
Inputs required	4	2
Result	Total IRS Penalties ($)	Marginal Tax Rate (%)
What it does	Estimate IRS penalties for late filing, late payment, or underpayment of estimated taxes based on the amount owed and how many days past the deadline you are. Helpful for taxpayers deciding whether to file for an extension or pay immediately.	Identifies your top marginal federal income tax bracket — the rate that applies to your next dollar of taxable income — based on 2023 IRS bracket thresholds and your filing status. Useful for marginal-rate decisions like Roth conversions, capital-gain harvesting, charitable bunching, and side-income trade-offs.