Free Tool · 2026

Quarterly Tax Calculator for Self-Employed & Small Business Owners

Enter your annual revenue, expenses, and filing status. Get your exact quarterly estimated tax payment — SE tax, federal income tax, and 2026 IRS due dates. No signup required.

Calculate Your 2026 Quarterly Estimated Taxes

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Your Estimated Quarterly Payment
$0
Self-Employment Tax
Federal Income Tax
Total Annual Tax
Recommended Set-Aside %
2026 IRS Quarterly Due Dates
Period IRS Due Date Pay This Amount
Jan 1 – Mar 31April 15, 2026
Apr 1 – May 31June 16, 2026
Jun 1 – Aug 31September 15, 2026
Sep 1 – Dec 31January 15, 2027
Federal estimate only. Does not include state income tax, additional deductions, prior-year safe harbor adjustments, or other individual circumstances. QBI deduction applied where eligible (phased out above income thresholds). Social Security wage base: $176,100. Consult a CPA for your final tax plan.

What Are Quarterly Estimated Taxes?

The U.S. tax system operates on a pay-as-you-go basis. When you work for an employer, they withhold income taxes and payroll taxes from each paycheck and remit them to the IRS throughout the year. When you're self-employed — whether as a freelancer, 1099 contractor, sole proprietor, or LLC — there's no employer doing that withholding. You do it yourself, four times a year.

If you expect to owe at least $1,000 in federal taxes for the year (after any withholding and credits), the IRS requires you to make quarterly estimated payments. Miss them — or pay too little — and you'll owe an underpayment penalty on top of your tax bill.

For most self-employed service business owners, the quarterly payment covers two separate obligations: self-employment (SE) tax and federal income tax. The calculator above computes both.

Who Owes Quarterly Taxes?

You most likely owe quarterly estimated taxes if any of the following apply:

If your employer withholds enough tax from a W-2 job to cover your total liability, you may not need to pay separately — but this is rare once self-employment income is significant. When in doubt, run the calculator and consult your CPA.

The Two Taxes Self-Employed People Pay

Most people new to self-employment focus only on income tax. The surprise is the second tax — self-employment tax — which is often just as large.

1. Self-Employment (SE) Tax

SE tax covers Social Security (12.4%) and Medicare (2.9%), totaling 15.3%. When you were employed, your employer paid half of this. Now you pay all of it. SE tax applies to 92.35% of your net self-employment income — the IRS adjusts the base downward to approximate what employees actually pay.

SE Tax Formula
SE Tax = (Net Profit × 92.35%) × 15.3%
Social Security applies only to the first $176,100 of SE income. Medicare applies to all earnings. An additional 0.9% Medicare surtax applies above $200,000 in net SE income.

For a business with $280,000 in net profit, SE tax alone comes to roughly $29,000 — before a single dollar of income tax. This is the number that surprises most first-time self-employed people at tax time.

2. Federal Income Tax

Federal income tax uses the same progressive bracket system as anyone else. But as a self-employed person, you get two important deductions first: a deduction for half your SE tax (the employer-equivalent portion) and the standard deduction. You may also qualify for the 20% QBI deduction on qualified business income, which can meaningfully reduce your taxable income if your earnings don't exceed the phase-out thresholds.

Example: On $280,000 net profit (single filer), you deduct ~$14,900 (half of SE tax) + $15,000 standard deduction + estimated QBI deduction, bringing taxable income to roughly $228,000. Federal income tax on that: approximately $52,000. Combined with SE tax of $29,000, total annual bill is ~$81,000, or ~$20,000 per quarter.

When Are Quarterly Tax Payments Due in 2026?

The IRS divides the year into four unequal payment periods. Each due date covers a specific income period:

Q1 2026
April 15, 2026
Q2 2026
June 16, 2026
Q3 2026
Sept 15, 2026
Q4 2026
Jan 15, 2027

Payments are made via IRS Direct Pay at irs.gov (free, no registration required) or by mailing IRS Form 1040-ES. Most states with income tax have their own separate quarterly payment requirements and schedules — California, for example, uses a 30/40/0/30 split rather than the federal equal-quarter structure.

How to Avoid the Underpayment Penalty

The IRS won't penalize you for underpaying as long as you meet one of the safe harbor thresholds:

The 110% rule is the simplest strategy for high-earning service businesses: take your last tax bill, add 10%, divide by 4, pay that amount each quarter. You may owe more at filing if 2026 was a bigger year — but you won't pay penalties.

Common Quarterly Tax Mistakes

1. Forgetting SE tax entirely. Most tax planning conversations focus on income tax brackets. But at 15.3% of net earnings, SE tax is often the larger of the two bills. The calculator above shows both separately so you see the real total.

2. Setting aside a percentage of revenue instead of profit. If you earn $400,000 but spend $180,000 running the business, setting aside 25% of revenue ($100,000) is actually 44% of your net profit. Always model set-aside rates against net profit — that's what gets taxed.

3. Not setting aside money weekly. Waiting until the quarterly due date to find the cash is how owners end up scrambling or underpaying. The discipline is simple: every time money hits your account, move a fixed percentage to a separate tax account. You never miss the money if you never count it as yours.

4. Ignoring state estimated taxes. If you operate in a state with income tax, you likely owe quarterly state estimated payments as well — with separate due dates, separate forms, and separate penalties. Add 3–9% to your federal rate depending on the state.

For more on how to model the full tax picture from your real weekly numbers, read our quarterly tax estimation guide — which walks through the complete $400K consulting firm example with every step of the math.

If you want to understand the profit margin behind your tax liability first — what gross margin, operating margin, and net margin actually mean for your business — see our profit margin calculator, which benchmarks your margins against industry standards for your business type.

Frequently Asked Questions

Do I have to pay quarterly taxes? +
If you expect to owe at least $1,000 in federal taxes for the year after subtracting withholding and credits, you are required to make quarterly estimated tax payments. Self-employed individuals, freelancers, 1099 contractors, and small business owners almost always meet this threshold. If you're unsure, run this calculator — if the result is more than $1,000 per year, you owe quarterly payments.
What happens if I miss a quarterly payment? +
If you miss a quarterly estimated tax payment or pay too little, the IRS charges an underpayment penalty calculated at approximately 7% annually on the shortfall, prorated by quarter. You can avoid the penalty entirely by meeting one of the safe harbor thresholds: pay 90% of this year's actual liability, or 100% (110% if AGI exceeds $150,000) of last year's total federal tax.
How do I pay quarterly taxes? +
The easiest method is IRS Direct Pay at irs.gov/payments — it's free, requires no registration, and processes same-day. You can also mail IRS Form 1040-ES with a check. EFTPS (Electronic Federal Tax Payment System) is another option popular with high-volume payers. Pay by the due date (April 15, June 16, September 15, January 15) to avoid penalties.
What is self-employment tax? +
Self-employment (SE) tax covers Social Security (12.4%) and Medicare (2.9%), totaling 15.3%. When you're an employee, your employer pays half. When self-employed, you pay the full 15.3%. SE tax applies to 92.35% of net self-employment income. Social Security applies only up to the wage base ($176,100 in 2026). Medicare applies to all earnings. An additional 0.9% Medicare surtax applies above $200,000 in net SE income.
What is the QBI deduction and do I qualify? +
The Qualified Business Income (QBI) deduction lets eligible self-employed individuals deduct up to 20% of qualified business income from taxable income. Most service-based businesses qualify below the income thresholds (~$197,300 for single filers, ~$394,600 for MFJ in 2026). Above those thresholds, the deduction phases out and may be eliminated entirely for certain professional service businesses. The calculator above estimates the QBI deduction where applicable.
Does this calculator include state taxes? +
This calculator computes federal taxes only (SE tax + federal income tax). State income tax is not included in the estimate because state rates, brackets, deductions, and quarterly payment schedules vary significantly. As a rough guide, add 3–9% of net profit for state income taxes depending on your state. States with no income tax (Texas, Florida, Nevada, Washington, Wyoming, South Dakota, Tennessee, Alaska) add zero. Consult your CPA or your state's revenue department for exact state quarterly payment requirements.

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