Quarterly Estimated Tax Calculator 2026 — Federal Payments & Safe Harbor

🗓️ Quarterly Estimated Tax Calculator

Enter your numbers to see your required annual payment and per-quarter breakdown.

💾 Save your inputs so you don't have to re-enter them next time.

💼Your Income

Filing Status

Expected Net SE/Business Profit ($/yr)

Other W-2 Wages ($/yr, if any)

Federal Tax Already Withheld ($/yr, from a W-2 job)

Qualifying Children Under 17

Other Dependents

📋Prior Year Figures (for Safe Harbor)Optional but recommended

Prior Year Total Federal Tax ($)

Prior Year AGI ($)

💡 Leave these at $0 if this is a new business with no prior year — the calculator will use the 90%-of-current-year method only.

How Quarterly Estimated Taxes Actually Work

If you're self-employed, run an S Corp, or have significant 1099/business income, the IRS expects you to pay taxes as you earn — not all at once in April. Estimated tax payments cover both your regular federal income tax and self-employment tax (Social Security + Medicare) on income that doesn't have anything withheld automatically.

You generally need to make estimated payments if you expect to owe $1,000 or more at tax filing time after subtracting withholding and credits.

The Safe Harbor Rule

You can avoid an underpayment penalty entirely by paying the smaller of these two targets over the year:

90% of your current year's total tax — requires a reasonably accurate estimate
100% of last year's total tax (or 110% if last year's AGI was over $150,000) — guaranteed safe regardless of how this year turns out, even if your income jumps

Most self-employed people with a growing business prefer the prior-year method — it's simpler and fully protects against a penalty even in a big growth year.

2026 Quarterly Due Dates

Payment	Due Date	Covers Income From
Q1	April 15, 2026	January – March 2026
Q2	June 15, 2026	April – May 2026
Q3	September 15, 2026	June – August 2026
Q4	January 15, 2027	September – December 2026

Notice the periods aren't equal — the IRS's quarters are 3, 2, 3, and 4 months long, respectively. This calculator still splits your required payment into four equal installments, which is the standard method most filers use.

⚠️ Missing a payment doesn't just delay things — the IRS calculates the underpayment penalty separately for each quarter. Catching up later in the year does not erase a penalty already accrued for an earlier quarter.

What This Calculator Includes

Self-employment tax (15.3% on 92.35% of net profit, with the Social Security portion capped at the 2026 wage base of $184,500)
The above-the-line deduction for half of your self-employment tax
2026 federal income tax brackets and standard deduction for both Single and Married Filing Jointly
Child Tax Credit ($2,200/child under 17) and Credit for Other Dependents ($500 each), with the 2026 phase-out applied above $200,000 (single) / $400,000 (MFJ) AGI
Safe harbor comparison against your prior year's actual tax liability

Your Numbers Are Completely Private

Every number you enter is processed entirely in your browser. Nothing is ever transmitted to a server, stored in a database, or shared with anyone.

⚠️ Important Limitations — Please Read

This calculator does not include state estimated taxes, which many states require separately and on their own schedule.
It does not include the 0.9% Additional Medicare Tax that applies above certain income thresholds.
It uses the standard equal-installment method, not the Annualized Income Installment Method for uneven income.
This is for educational and planning purposes only, not tax advice. Consult a licensed CPA or tax professional for your specific situation.

Frequently Asked Questions

How much should I pay in quarterly estimated taxes?

You're generally safe from an underpayment penalty if you pay the smaller of 90% of your current year's tax liability or 100% of last year's tax liability (110% if last year's AGI was over $150,000). This is the "safe harbor" rule.

What happens if I miss a quarterly payment?

The IRS charges an underpayment penalty calculated separately for each quarter, at the federal short-term rate plus 3 percentage points, compounded daily. Catching up in a later quarter does not erase the penalty for an earlier missed one.

Do I need to make estimated payments if I also have a W-2 job?

Not necessarily. If your W-2 employer withholds enough extra tax to cover your self-employment income, you may not need to make separate quarterly payments at all. Increasing your W-4 withholding is often simpler than sending quarterly checks.

What if my income changes a lot throughout the year?

This calculator uses the standard equal-quarterly-installment method. If your income is uneven (e.g., seasonal work), the IRS also allows the Annualized Income Installment Method (Schedule AI on Form 2210), which can reduce or eliminate penalties for quarters where you earned less.

Does this calculator account for kids or other dependents?

Yes — it applies the 2026 Child Tax Credit ($2,200 per qualifying child under 17) and Credit for Other Dependents ($500 each) directly against your federal income tax, including the phase-out that begins at $200,000 AGI (single) or $400,000 AGI (married filing jointly). These credits reduce your income tax but not your self-employment tax.

Quarterly Estimated Tax Calculator2026 Payments & Safe Harbor