Federal safe-harbor planner

2026 Quarterly Tax Calculator

Estimate the smaller federal safe-harbor target, remaining annual payment and equal quarterly installments.

Safe-harbor modesRates: 2026Updated August 5, 2026
Enter your numbers
Estimated result
Estimated quarterly installment$4,000
Required annual-payment target$20,000
90% current-year method$21,600
100% prior-year method$20,000
Remaining after withholding$16,000

Equal-installment federal safe-harbor planner. Verify due dates and consider the annualized-income method if income is uneven.

Inputs stay in this browser and are never uploaded.
How it works

Required annual payment

Formula

Safe-harbor target = the smaller of 90% of expected current-year tax or 100% of prior-year tax (110% for certain higher-income taxpayers), less expected withholding.

This calculator helps plan equal federal installments. It does not calculate annualized-income installments for uneven earnings.

The statutory quarters are not equal calendar quarters, and due dates can move for weekends, holidays or disaster relief. Always verify the current IRS schedule.

Assumptions and limits

  • Prior-year return covered 12 months
  • Four equal installments
  • No farmer/fisher special rule
  • Federal payments only
Planning estimate, not tax advice

Tax law depends on facts this tool cannot collect. Do not use the result as the sole basis for filing, withholding or payment decisions.

Frequently asked questions

Which safe-harbor method does the calculator use?

It uses the smaller of 90% of expected current-year tax or the applicable prior-year percentage, then subtracts expected withholding.

When does 110% apply?

For 2026, the prior-year percentage generally becomes 110% when 2025 AGI exceeded $150,000, or $75,000 if filing separately.