Quarterly Estimated Tax Calculator

Estimate your quarterly federal estimated tax payments (Form 1040-ES). Simplified calculator with 2026 safe harbor rules for self-employed individuals.

Tax Inputs

$
Total federal income tax before credits
$
From SE Tax Calculator or main calculator
$
Credits & Withholding
$
$
$
Prior-Year Safe Harbor (Optional)
$
$

Quarterly Payment

Estimated Quarterly Payment
$0.00
Per quarter
BreakdownAmount
2026 Due Dates: Q1 Apr 15, Q2 Jun 15, Q3 Sep 15, Q4 Jan 15, 2027
Disclaimer: This is a simplified 1040-ES estimator. It does not model: non-itemized charitable deductions, Schedule 1-A, AMT, other taxes, prior-year overpayment carryforward, or missed-quarter tracking. The output is a theoretical equal quarterly installment, not the amount still due today. Nonrefundable and refundable credits only affect the quarterly safe harbor calculation, not your actual tax liability. Consult a tax professional for exact figures.

How Quarterly Estimated Taxes Work

If you're self-employed, you generally need to make quarterly estimated tax payments to the IRS instead of having taxes withheld from a paycheck. Here's how it works:

$1,000 Threshold

If you expect to owe at least $1,000 in federal tax after withholding and credits, you must make quarterly estimated payments to avoid underpayment penalties.

90% Current-Year Rule

You avoid penalties if your total payments (withholding + estimated) cover at least 90% of your current-year tax liability. This is the "current-year safe harbor."

Prior-Year Safe Harbor

Alternatively, you avoid penalties if you pay 100% of your prior-year tax (110% if prior-year AGI exceeded $150,000, or $75,000 for MFS). Use whichever safe harbor results in a lower payment.

1040-ES Calculation Order

Federal income tax − nonrefundable credits + SE tax + full-year Additional Medicare − refundable credits − withholding = estimated balance. If ≥ $1,000, divide the required annual payment by 4.

2026 Quarterly Due Dates

Frequently Asked Questions

When are quarterly estimated taxes due?

Quarterly estimated tax payments are due April 15, June 15, September 15, and January 15 of the following year. For 2026: Q1 April 15, Q2 June 15, Q3 September 15, and Q4 January 15, 2027. If a due date falls on a weekend or holiday, it shifts to the next business day.

What is the quarterly tax safe harbor?

You avoid underpayment penalties if you pay at least 90% of your current-year tax liability or 100% of your prior-year tax (110% if your prior-year AGI exceeded $150,000, or $75,000 for MFS). Use whichever safe harbor results in a lower required payment. If your prior-year tax was $0 (because you had no income or filed for the full 12 months), the safe harbor is $0.

Do I need to pay quarterly estimated taxes?

You must make quarterly estimated payments if you expect to owe at least $1,000 in federal tax after withholding and credits. Self-employed individuals without W-2 withholding typically need to pay quarterly. If you also have a W-2 job, you can increase your W-2 withholding to cover the 1099 tax instead of making separate quarterly payments.

How do credits affect quarterly payments?

Nonrefundable credits reduce your federal income tax (but cannot reduce it below zero or offset SE tax). Refundable credits reduce your total tax liability dollar-for-dollar. Both types of credits only affect the quarterly safe harbor calculation, not your actual incremental tax burden from 1099 income.