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Rubric Financial

Free Calculator

Quarterly Estimated Tax Calculator

Picks the cheaper of two IRS safe harbors and divides into four quarterly payments. Federal only, state estimates run on separate schedules.

Your situation

Pick whichever safe-harbor method is cheaper. The prior-year method is the most predictable, it locks in your minimum required.

Each quarterly estimate

$11,000

due Apr 15, Jun 15, Sep 15, and Jan 15 (next year)

Prior-year safe harbor (110%)$44,000
90% of current-year tax$45,000
Method chosenPrior-year safe harbor (110% of last year's tax)
Target total payments this year$44,000
Less W-2 withholding-$0
Required estimates total$44,000

Read this carefully

Federal only. State estimates (especially California's 30/40/0/30 schedule) are separate. Q2 covers only Apr–May; Q3 covers Jun–Aug. Pay via IRS Direct Pay or EFTPS. Check your safe harbor.

Estimates for educational purposes only, not tax, legal, investment, or accounting advice. Your specific facts will change the result; confirm with a CPA before acting.

Email me what to do with this number.

Next: picking a safe harbor, handling uneven income, and keeping the underpayment penalty off your return. We send short, partner-written reads on tax, accounting, and finance, and nothing else. The calculator itself stays free and needs no sign-up. No spam, unsubscribe anytime.

Want help with multi-state estimates?

California, New York, and other states each have their own estimated-tax schedules and safe-harbor rules. We handle federal and multi-state estimates as part of every tax engagement.

Read the guide

Frequently Asked

Quarterly estimated tax questions

Who has to pay quarterly estimated tax?
Anyone who expects to owe $1,000+ in tax after withholding and refundable credits. Typically: self-employed individuals, partners, S-corp shareholders, landlords, and high-investment-income earners. Corporations have separate rules (Form 1120-W).
What is the safe harbor?
Pay at least 90% of current-year tax OR 100% of prior-year tax (110% if prior-year AGI exceeded $150,000), whichever is less. Meeting either avoids the underpayment penalty even if you owe a large balance at filing.
When are quarterly estimates due?
April 15 (Q1, covers Jan–Mar), June 15 (Q2, covers Apr–May), September 15 (Q3, covers Jun–Aug), and January 15 of the following year (Q4, covers Sep–Dec). These are not calendar quarters.
Does this calculator handle state estimates?
No, federal only. State estimates vary widely. California, for example, uses a 30/40/0/30 split on different dates. Check your state's department of revenue or use a CPA for state-specific cadence.

Keep reading

Glossary

W-2

IRS form reporting wages, tips, and tax withholding for employees.

Glossary

Estimated Tax Payments

Quarterly tax payments owners and corporations send in throughout the year to cover income and self-employment tax the IRS expects them to owe.

Glossary

Backup Withholding

A mandatory 24% federal tax withholding a business must take out of payments to a payee who won't provide a valid taxpayer ID.

Glossary

Tax Withholding

Income and payroll tax an employer takes out of each paycheck and remits to the government on the employee's behalf.

Guide

Quarterly Estimated Tax for Self-Employed and Business Owners

If you're not on a W-2, the IRS expects four prepayments a year. Miss them and you owe penalties even if you pay in full at filing.

Guide

Multi-State Payroll Setup for Small Businesses

One remote employee in another state means new tax registrations, withholding rules, and compliance work. Here's the playbook.