Free tool
Quarterly estimated tax calculator
Four payments, penalty-proofed.
Your result is an estimate based on the answers you enter. It is not filed or stored anywhere.
Method
How this calculator works
The IRS never penalizes you for underpaying estimated tax if your four payments total 100% of last year's total tax — 110% if last year's adjusted gross income exceeded $150,000. That number sits on last year's Form 1040 as "total tax."
This calculator applies the safe harbor, subtracts any withholding you expect from a W-2 job (withholding counts as if paid evenly through the year), and splits the rest into four installments against the actual due dates. If this year's income has dropped sharply, paying 90% of a current-year estimate may be less — see the full quarterly-taxes guide.
Estimates, not advice
Every figure this tool produces is a planning estimate built from the numbers you enter and simplified assumptions documented above. It is educational content, not individualized financial, legal, or tax advice. Rates, limits, and thresholds change — annual constants are reviewed each January, and you should confirm anything decision-critical against primary sources or a professional.
Questions
FAQ
What if my income jumps this year?
The safe harbor still protects you from penalties. You'll owe the difference at filing, but with no penalty — and you had use of the cash all year.
Where do I find "total tax"?
On last year's Form 1040 — the line labeled "total tax" (line 24 on recent forms), not the refund or balance-due line.
How do I actually pay?
IRS Online Account or IRS Direct Pay, choosing "Estimated tax — 1040-ES" and the correct year. Most states run a parallel system with the same dates.